J. Nannoplankton Res. 37 (2–3), 2017, pp.215–244 © 2017 International Nannoplankton Association
ISSN 1210-8049 Printed by The Sheridan Press, USA

215

Uppermost Oligocene to Middle Miocene Discoasterand Catinaster taxonomy and stratigraphy in the circum
North Atlantic Basin: Gulf of Mexico and ODP Leg 154
Eric de Kaenel*
DPR, Chemin sous la Roche 4b, 1185 Mont-sur-Rolle, Switzerland; *edekaenel@bluewin.ch

Jim Bergen
Paleo @ the Hill Country, Brenham, TX 77833, USA; jbnanno@att.net

Emily Browning
BP America, 200 Westlake Park Blvd, Houston, TX 77079, USA; Emily.Browning@bp.com

Stacie Blair
Blair Biostratigraphy, Cypress, TX 77429, USA; stacie.blair81@gmail.com

Todd Boesiger
Ellington ALS Oil & Gas, Houston, TX 77043, USA; Todd.Boesiger@alsglobal.com
Manuscript received 30th September, 2016; revised manuscript accepted 9th July, 2017

Abstract The genus Discoaster is of primary significance for Neogene nannofossil biostratigraphy in the Gulf of

Mexico. The taxonomy and biostratigraphy of seven Lower to Middle Miocene Discoaster groups are discussed andillustrated in this paper. Detailed taxonomic descriptions are supported with drawings and light photomicrographs
to clarify taxonomic concepts. The species, emendations, and new species presented detail the concepts and ages
utilized by BP in the Gulf of Mexico. The stratigraphic occurrences of calcareous nannofossils for the Gulf of Mexico
are calibrated to the astronomical chronometer of ODP Leg 154 in the western equatorial Atlantic. The base of the
Neogene was investigated by sampling the Global Boundary Stratotype Section and Point from the Lemme-Carrosio
section in northern Italy. A new Zone (NP26) is introduced for the terminal Oligocene, and Zone NN1 is emended sothat the NP/NN zonal boundary is now tied to the Paleogene/Neogene boundary. Fifty main biostratigraphic eventsare presented for the Gulf of Mexico and ODP Leg 154 from 23.155Ma to 9.826Ma. Two new Catinaster species
are described: C. glenos and C. rotundus. Eighteen new Discoaster species are described: D. apetalus, D. arneyi,
D. carneyi, D. catillomicros, D. catinatus, D. cuspidatus, D. discissus, D. durioi, D. emblematicus, D. gamberi,
D. hexapleuros, D. leroyi, D. patulus, D. premicros, D. salomonii, D. shumnykii, D. stellimicros, and D. ulnatus. One
new combination is introduced, Discoaster virginianus.

Keywords Catinaster, Discoaster, nannofossils, Oligocene, Miocene, Gulf of Mexico, GSSP, taxonomy, Leg
154, biostratigraphy

1. Introduction
The merger of BP with Amoco and Arco Vastar prompted
the integration of the three heritage company Cenozoic
biostratigraphic frameworks for the Gulf of Mexico (GoM)
into a single BP framework. Subsequently, a twelve-year
research program was initiated to calibrate the BP GoM
framework to ODP Leg 154 (Figure 1) from the Ceará Risein the western equatorial Atlantic. This research program
also included work on the Oligocene-Miocene boundary
Global Boundary Stratotype Section and Point (GSSP) in
Italy (de Kaenel & Bergen, 2008; Bergen et al., 2009; deKaenel & Villa, 2010). These efforts yielded an astronomically-tuned Neogene time scale for the early Oligocene(30.679Ma) through early Pleistocene (1.595Ma) for the
GoM and western equatorial Atlantic that has an averagebiostratigraphic resolution of 141ky. To our knowledge,
this is the only fully astronomically-tuned industrial timescale. The BP Gulf of Mexico Neogene Astronomically
Tuned Time Scale (BP GNATTS) is currently in preparation for publication and contains the details of the age
model, biostratigraphic horizon nomenclature, and event
stratigraphy and calibration (Bergen et al., in prep). The
age model derived from Leg 154 is based on the astronomically-tuned cycles developed by Shackleton & Crowhurst(1997) and Pälike et al., (2006) and was recalibrated to theorbital solution of Laskar et al., (2004). High resolution
sampling was employed with an average of 21ky, approximately equal to that of a precession cycle. A detailed description of the age model with methodology, sample depths,
and ages will be presented in Bergen et al., (in prep).

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de Kaenel et al.

120°0'0"W

90°0'0"W

60°0'0"W

30°0'0"W

0°0'0"

30°0'0"E

Lemme-Carrioso
Leg 149
Sites 897-900

Atlantic
Ocean

30°0'0"N

Gulf of Mexico
Leg 68Site 502

TrinidadLeg 154
Sites 925-929

Figure 1: Map showing the locations of sample materials utilized and discussed in this study: the Ceará Rise (ODP Leg 154, Site 926), the Columbia
Basin, western Caribbean Sea (DSDP Leg 68, Site 502), Trinidad, Galicia Margin (ODP Leg 149, Sites 897–900), Lemme-Carrioso (Italy) and the
Gulf of Mexico

Extensive taxonomic discussions of BP species concepts and revisions of some Neogene species are provided
in the five BP papers within this journal (Bergen et al., 2017;
Blair et al., 2017; Browning et al., 2017; Boesiger et al., 2017;
this paper) and must precede publication of the BP Neogene biostratigraphic chart (BP GNATTS; Bergen et al.,in prep). The taxonomy and biostratigraphy of the genus
Catinaster and the Upper Oligocene to lower Middle Miocene Discoaster are the focus of this paper. The utility ofthese groups in Upper Oligocene to lower Upper Miocene
GoM sediments is greatly expanded, including the calibration of 50 main biostratigraphic events and the descriptionof 20 new taxa.
2. Material and methods
The materials used for this study are from outcrops, core,
and well cuttings (Figure 1). Most of these were collectedfrom ODP cores of Leg 154 at the IODP repository in Bremen (Germany). ODP Leg 154 is situated on the Ceará Risein the western tropical Atlantic. Other DSDP/ODP samples are from Leg 68, Hole 502 (Colombia Basin, Western
Caribbean Sea) and Leg 149, Holes 897C, 898A, 899A,
899B and 900A (northeast Atlantic Ocean). Additional
samples were examined from the Bolli collection sampledby H.M. Bolli in 1957 in Trinidad (Bolli, 1957), deepwater GoM well materials (predominantly ditch-cutting
samples), and sections from the historical stratotype of the
Aquitanian stage (Aquitaine, Southwest France). Specimens illustrated herein were recovered from five Trinidad
samples: (1) Bo267, Catapsydrax dissimilis Zone, Zone
NN2; (2) PJ260, Globorotalia fohsi fohsi Zone, Zone NN4;
(3) JS32, Globorotalia fohsi lobata Zone, Zone NN6;
(4) Bo355, Globorotalia fohsi robusta Zone, Zone NN7;and (5) KR23422, Globorotalia menardi Zone, Zone NN9.
The low-latitude composite section from ODP Leg
154 was sampled at an average resolution of 21ky fromthe Lower Oligocene (30.679Ma) to the Lower Pleistocene (1.595Ma); a total of 1366 samples were examined.
Thirty-nine samples collected from the Lemme-Carrosio
section in northern Italy, the base of Neogene GSSP, were
examined to help resolve nannofossil boundary criteria
for upper Zone NP25 to basal Zone NN2. The following
stratigraphic abbreviations are used: LO (lowest occurrence) and HO (highest occurrence); abundance modifiers
are: R (regular or persistent) for LRO and HRO, F (few)for LFO and HFO, C (common) for LCO and HCO, A(abundant) for LAO and HAO, and Acme.
The objective of this work is to clarify taxonomic concepts and present the GoM stratigraphy developed overthe past five decades within the three BP heritage companies (Amoco, Arco Vastar and BP), not to compare ourresults to other published stratigraphies of the GoM Basinor research on ODP Leg 154. The geologic ages derived
from sampling of ODP Leg 154 are maintained at threedecimal precision through the manuscript for consistency.
Errors presented for ages are the difference in age for the
next sample analyzed upwards or downwards in the composite section.
3. Biostratigraphy
Historically, industrial schemes use tops (HO) and assemblage changes as criteria; however, fossil bases (LO) are
now routinely utilized in modern GoM wells because
downhole caving is rarely problematic. The use of fossil
bases not only enhances biostratigraphic resolution andinterpretations in wells, but makes possible direct calibration to published schemes in their entirety. Calibration to
published Cenozoic nannofossil zonations (Martini, 1971;
Okada & Bukry, 1980) is effective because of their global
reach, long term use and communication of results. The
Cenozoic zonation of Martini (1971) is our main reference for the GoM. The GoM heritage schemes have long

…Discoaster and Catinaster taxonomy and stratigraphy…

indicated problems with the application of the Martini(1971) zonation around the Paleogene-Neogene boundary(Zones NP 25 and NN1), both in terms of the sequence of
events and calibration to the boundary. This issue can now
be resolved with the addition of internal research on theratified base Neogene reference section in northern Italy(GSSP) and the astronomical chronometer of ODP Leg
154. The BP GNATTS is based on calcareous nannofossils
and foraminifera; a full description of this zonation will be
provided Bergen et al., (in prep).
The top of the Sphenolithus ciperoensis Zone (NP25)
of Martini (1970; 1971) was originally defined on the HO
of Helicosphaera recta by Bramlette & Wilcoxon (1967a).
BP has long recognized the HO of both H. truncata andH. recta (other authors consider H. truncata a junior synonym of H. recta) within Zone NN2 in the GoM, and now
Leg 154, where they are dated at 21.041Ma and 20.170Ma,
respectively (Boesiger et al., 2017; this volume). Martini(1986) proposed another event as a substitute, the HO
of Zygrhablithus bijugatus, which we have observed torange far up into the Lower Miocene. Bukry & Bramlette(1970) used the extinctions of both S. ciperoensis and Dictyococcites bisectus to mark the top of the S. ciperoensis
Zone. Both of these events were later adopted by Bukry(1973a/b, 1975) to mark the top of his S. ciperoensis Zone,
later coded as Zone CP19 in Okada & Bukry (1980). The
extinction of S. ciperoensis, which represents the end ofa lineage, is dated at 24.215Ma (Bergen et al., 2017; thisvolume) and falls 1.185Ma below the base of the Neogene. Dictyococcites bisectus is problematic in that the
species may or may not be distinguished from the larger
D. stavensis. Furthermore, D. bisectus ranges up into theLower Miocene in both the GoM and Leg 154, dated in
the latter at 19.011Ma (926B-38X-5, 135–137cm; error
0.020Ma).
We propose a new zone (NP26) to be placed between
the top of Zone NP25 and the base of Zone NN1. Okada& Bukry (1980) showed an informal Zone NP26 in their
Table II (between Zones NP25 and NN1), corresponding
to their Cyclicargolithus abisectus Subzone (CN1a). Thebase of Subzone CN1a is defined by the HO of both Sphenolithus ciperoensis and Dictyococcites bisectus and the
top by the end acme of Cyclicargolithus abisectus. The
C. abisectus acme is placed 0.804 million years below
the base of the Neogene in Leg 154 at 23.834Ma (Sample
926B-52X-5, 110–111cm; error 0.020Ma). Our new Clausicoccus fenestratus Zone (NP26) utilizes a proven Oligocene marker (HO of S. ciperoensis) and a solution whichcalibrates the NP26/NN1 zonal boundary to the base of
the Neogene.
NP26 – Clausicoccus fenestratus Zone
Definition: Interval from the HO of Sphenolithus
ciperoensis to LO of Discoaster druggii (10#m to <15#m)
Authors: de Kaenel & Bergen, this paper
Reference locality: Ocean Drilling Project Leg 154

217

Remarks: The HO of S. ciperoensis is placed in Sample 926B-53X-5, 70–71cm, dated at 24.215Ma (error
0.022Ma). The LO of medium-sized Discoaster druggii(10 to <15μm) is dated at 23.030Ma in the Leg 154
research (Table 1).
Discussion: Steininger et al., (1997) placed the base of
the Neogene at 35 meters (GSSP) in the Lemme-Carrosio
reference section, but we were unable to locate the LO
of Discoaster druggii (10 to <15μm) in that section. The
HO of S. ciperoensis was placed at 60.0 meters in the
Lemme-Carrosio section.
NN1 – Triquetrorhabdulus carinatus Zone - emended
Definition: Interval from the LO of Discoaster druggii(10#m to <15#m) to LO of Discoaster druggii bUD@#m)
Authors: Bramlette & Wilcoxon (1967a), emended deKaenel & Bergen, this paper
Reference locality: Ocean Drilling Program Leg 154
Remarks: In the Leg 154 research, the LO of medium-sized Discoaster druggii (10 to <15μm) is dated at
23.030Ma, and the LO of large of D. druggii bUD@#m)is dated at 22.757Ma (Table 1). The HO of Sphenolithus
capricornutus serves as a proxy for the base of the Neogene in an operational sense, being dated at 22.998Ma in
the Leg 154 research (Bergen et al., 2017; this volume).
Discussion: The LO of Discoaster druggii is the original
marker for the base of Zone NN2 (Martini & Worsley, 1970;
Martini, 1971). We have separated this species into three size
categories, which have proven stratigraphic utility. Regarding their originations, these events (Table 1) are the:(1) LO of small D. druggii (<10μm) in the terminal
Oligocene at 23.155Ma;(2) LO of medium D. druggii (10 to <15μm) at thebase Neogene at 23.030Ma; and(3) LO of large D. druggii bUD@μm) is recorded at
22.757Ma.
The holotype of this species is 18.50#m. Utilization of*HL Ei,IL 30,.H0*e.L bUD@μm) to mark the base of Zone
NN2 conforms to the original definition of the species,
whereas the origin of the medium-sized D. druggii marries
the base of Zone NN1 to the base of the Neogene.
4. Systematic palaeontology
In Oligocene to Pliocene sediments, six-rayed variants of
Discoaster are the dominant (i.e., more diverse and abundant) forms. A notable exception is seen in the Late Miocene when five-rayed taxa of the D. quinqueramus andD. prepentaradiatus groups were common. In many of the
Discoaster groups, distinct forms can be differentiatedby the number of rays, which can vary from three to seven,and by whether or not the asterolith is symmetric or asymmetric. Many of these forms have different stratigraphic
ranges, making their taxonomic separation useful.
Browning et al., (this volume) and Blair et al., (this volume)detail these variations in ray number and form in Late
Miocene to Pliocene species of Discoaster.

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de Kaenel et al.

Taxon

Event

Zone
Martini 71

Age
(Ma)

Error1(Ma)

C. coalitus

HO/HROD. microsHO

C. coalitus (>10μm)
C. coalitus
C. coalitus

Hole-Core-Sec.
cm-cm

Depth
(rmcd)2

NN9

9.826

0.023

926A-24H-3, 60–62cm

241.21NN910.082

0.017

926A-24H-5, 107–109cm

244.68HONN910.403

0.024

926A-25H-1, 35–37cm

248.71INC

NN910.403

0.024

926A-25H-1, 35–37cm

248.71

LFO/LCONN910.732

0.020

926A-25H-3, 67–69cm

252.03D. emblematicus

HO

NN8

11.037

0.011

926A-25H-5, 131–133cm

255.67D. cuspidatus

HO

NN8

11.037

0.011

926A-25H-5, 131–133cm

255.67

D. ulnatus

HO

NN8

11.037

0.011

926A-25H-5, 131–133cm

255.67

D. hexapleuros (knob)

HO

NN8

11.155

0.022

926A-25H-6, 103–105cm

256.89D. patulus

HO

NN8

11.5090.019

926A-26H-2, 26.5–28.5cm

262.14

D. kugleri

HO/HRO

NN8

11.5090.019

926A-26H-2, 26.5–28.5cm

262.14HONN8

11.531

0.004

926A-26H-2, 51.8–53.8cm

262.39C. coalitus

LObase NN8

11.531

0.011

926A-26H-2, 51.8–53.8cm

262.39D. deflandrei

HO/HRO

NN7

11.575

0.033

926A-26H-2, 108–110cm

262.95

D. kugleri

HCO

NN7

11.575

0.033

926A-26H-2, 108–110cm

262.95

D. kugleri

acme

NN7

11.625

0.036

926A-26H-2, 141.5–143.5cm

263.29D. kugleri

LCO

NN7

11.7600.015

926A-26H-3, 141–143cm

264.78

D. sanmiguelensis

HO

NN7

11.8490.023

926A-26H-4, 112–114cm

265.99D. kugleriLObase NN7

11.9100.005

926A-26H-5, 55–57cm

266.92D. hexapleuros

D. hexapleuros

LO

NN6

11.962

0.025

926A-26H-6, 12.5–14.5cm

268.00D. sanmiguelensis

HRO

NN6

12.173

0.019

926A-27H-1, 131–133cm

271.53D. hexapleuros (knob)

LO

NN6

12.186

0.018

926A-27H-2, 15.5–17.5cm

271.88D. cuspidatus

LRO

NN6

12.968

0.021

926A-28H-3, 57.5–59.5cm

283.78D. cuspidatus

LO

NN6

13.027

0.021

926A-28H-4, 26–28cm

284.96

D. musicus

HO

NN6

13.067

0.019

926A-28H-4, 107.5–109.5cm

285.78D. cuspidatus (knob)

LO

NN6

13.217

0.023

926A-28H-6, 10.5–12.5cm

287.81

D. petaliformis

HO

NN5

13.637

0.024

926A-29H-5, 125–127cm

296.95D. druggii (<10)

HO

NN5

13.856

0.023

926A-30H-1, 37–39cm

300.48

D. arneyi

HONN5

14.091

0.011

926A-30H-4, 51–53cm

305.12

D. premicros

HO

NN5

14.1890.009

926A-30H-5, 59.5–61.5cm

306.71

D. deflandrei

INC

NN5

14.3200.004

926A-30-CC, 5–7cm

309.82

D. druggii (10<15)

HO

NN5

14.3200.004

926A-30-CC, 5–7cm

309.82

D. premicros

HRO

NN5

14.397

0.019

925A-4X-5, 49–50cm

358.54

D. musicus

LO

NN5

14.4970.020

925C-35X-2, 30–31cm

364.98

D. premicros

INC

NN5

14.5390.022

925C-35X-2, 115–117cm

365.84D. petaliformis

acme

NN5

14.6170.018

925C-35X-3, 120–122cm

367.38

D. salomonii

HO

NN4

15.0980.019

925D-35H-6, 50–52cm

371.69D. leroyi

HRO

NN4

15.3790.022

925C-37X-2, 40–41cm

385.63

D. premicros

LO

NN4

15.4980.021

925C-37X-4, 30–32cm

388.54D. petaliformis

LO

NN4

15.7780.019

925D-37H-4, 40–41cm

397.79

D. arneyi

LONN4

15.8570.019

925C-38X-2, 90–91cm

404.34

D. deflandrei

HCO

NN4

16.537

0.020

925A-9H-6, 20–22cm

408.05D. shumnykii

HRO

NN4

17.2580.020

928B-27X-5, 70–71cm

269.64

D. deflandrei

HAO

NN4

17.4560.031

928B-28X-2, 15–16cm

274.29D. druggii (≥15)

HRO

NN4

17.6090.022

928B-28X-3, 145–146cm

277.09D. calculosus

HO

NN3

18.132

0.020

926C-36X-1, 75–77cm

356.75

D. saundersii

HO

NN3

18.8520.020

926B-38X-3, 15–17cm

378.67

D. druggii (≥15)

LO

base NN2

22.7570.020

928B-36X-6, 100–102cm

358.24D. druggii (10<15)LObase NN1

23.0300.008

926B-50X-5, 23–24cm

497.44D. druggii (<10)

LO

NP26

23.155

0.018

929A-35X-3, 125–127cm

340.07

Table 1: Main events for the discussed Discoaster and Catinaster groups as observed in Leg 154 and Gulf of Mexico. 1error in age of next sample.
2revised meters composite depth

…Discoaster and Catinaster taxonomy and stratigraphy…

Late Oligocene to Middle Miocene Discoaster species are discussed herein, and 18 new species are introduced. The genus Catinaster is also considered, with theintroduction of two new species. Catinaster virginianus
Self-Trail (2014) is transferred to the genus Discoaster.
Seven groups of Discoaster and the genus Catinaster
have been systematized according to their morphologic
similarities, each group named after a representative species. The D. druggii and D. kugleri groups have featureless central areas and simple ray terminations. These twogroups are iterative and are best separated by geologic
age. The D. deflandrei group has complex “wrenched”
bifurcations and includes forms with both ornate andfeatureless central areas. The D. sanmiguelensis grouphas small, clubbed terminations and ornate central areas.
Discoaster musicus shares this morphology but is distinguished by its large, stellate knob that extends to the central area periphery. Therefore, this distinct feature allows
recognition of a separate grouping and remains diagnostic of the entire D. musicus group, which have variable
ray morphologies. Species with flat ray terminations withvariable central area morphologies are characteristic of
the D. micros group. The D. petaliformis group consists
largely of six-rayed asteroliths with high stems and/or
bifurcate ray terminations.
Morphologic terminology follows the guidelines ofYoung et al., (1997). The distal face is the convex sidewith sutural ridges. The proximal face is the concave side.
A knob is a rounded, central structure usually located on
the proximal side. A stem is a stellate, central structure on
the distal or proximal side. The following size categories
are utilized in this study: very small (<5μm); small (5 to<10μm), medium (10 to <15μm); large (15 to <20μm);
very large bUCZμm).
4.1 Discoaster druggii group
This group has featureless central areas and tapered rays
with simple terminations. These terminations may berounded, notched or truncate. Lateral nodes may be present but are not diagnostic of species. The D. kugleri groupshares these morphological features, but evolved during
the Middle Miocene about 639ky after the extinction of
the D. druggii group (Figure 2). Three species are considered in the D. druggii group, including the new species
D. shumnykii.
Genus Discoaster Tan, 1927
Discoaster druggii Bramlette & Wilcoxon, 1967aPl. 1, figs 1–5, 7–10, 12–18
1967a Discoaster extensus Bramlette & Wilcoxon, p. 110,
pl. 8, figs. 2–8
1967b Discoaster druggii Bramlette & Wilcoxon, p. 220,
nom. nov. pro Discoaster extensus Bramlette & Wilcoxon
1967, non Discoaster extensus Hay 1967
Remarks: Discoaster druggii has a large central areaand long rays. Bramlette & Wilcoxon (1967a) gave a size

219

range of 15–22#m for the species. The holotype (18.5μm)
was recovered from the Burdigalian Catapsydrax dissimilis Zone (NN2), and this type sample material (Bo267)
has been used in this study to illustrate additional specimens (Pl. 1; figs. 5, 10, 16–18). We have divided this species into three size categories separated at 10 and 15μm.
Discoaster shumnykii differs from D. druggii by its shortrays. The free ray length to central area ratio is greaterthan one-third for D. druggii (0.36–0.71 ratio), based on
22 measured specimens (Bramlette & Wilcoxon, 1967a;
this paper).
Occurrence: The sequence of bases for the threesize categories of D. druggii is well-established in Leg
154 (Table 1; Figure 2). Utilized as events in the GoM,
their extinctions occur in reverse order and have beencalibrated to ODP Leg 154 as follows: HO of large
D. druggii bUD@#m) at 17.347Ma (928B-27-CC, 30–32cm;
error 0.009Ma), HO medium D. druggii (10 to <15#m)
at 14.320Ma, and the HO of small D. druggii (<10#m)
at 13.856Ma (Table 1). The HRO of large D. druggii
is a GoM marker dated at 17.609Ma, along with the
HO of both the small and medium-sized morphotypes(Table 1).
Discoaster shumnykii de Kaenel & Bergen, sp. nov.
Pl. 1, figs 6, 11; Pl. 3, figs 1–5
Derivation of name: In honor of nannofossil biostratigrapher Anatoliy Shumnyk (Bugware Inc., Tallahassee, FL,USA)
Description: A small to medium-sized Discoasterwith short, tapering free rays and slightly indented ray terminations. The free rays may have small lateral nodes. Theinter-ray areas are rounded and shallow. The large central
area is featureless and divided by linear sutures that extend
to the center of the asterolith.
Remarks: Discoaster shumnykii has shorter rays thanD. druggii. For D. shumnykii, the free ray length to central area ratio less than one-third (0.21–0.28 on six measured specimens). Discoaster obtusus is a thicker form
with more pointed ray tips. Discoaster shumnykii may beancestral to both D. obtusus and D. druggii. Discoasterkugleri is morphologically similar to D. shumnykii, but
their stratigraphic ranges are separated by approximately
5.27My. Discoaster shumnykii has been referred to as“D. druggii (stubby)” in the BP GoM lexicon.
Holotype dimension: 9.4#m
Holotype: Pl. 3, figs 2–3
Type locality: South Trinidad, from Bolli (1957)
Type level: Sample Bo267, Catapsydrax dissimilis
Zone, Cipero Formation, Zone NN2
Occurrence: Discoaster shumnykii ranges from
Upper Oligocene (NP25) to Lower Miocene (NN4), dated
at 17.178Ma (928B-27X-4, 55–56cm; error 0.021Ma) in
the Leg 154 research. The HRO of D. shumnykii is a BP
GoM marker dated at 17.258Ma in the Leg 154 research(Table 1, Figure 2).

220

11.5

CN7a
NN8

CN6

NN7

CN5b

11.037

11.63

Serravallian

12.0
12.5

MIDDLE

13.0
13.5
14.0

NN6

12.186

11.53111.96211.509
HCO-11.575
acme-11.625
LCO-11.760

11.910

LRO12.968

13.02713.85613.82

CN414.320Langhian

15.0

11.15513.217

NN5

14.5

CN5a

11.037

D. kugleri

11.0

NN9

HO2.286

CN7b

D. hexapleuros sp. nov.

LATE
Tortonian

10.5

Okada
Martini & Bukry(1971) (1980)

D. hexapleuros
sp. nov. (knb)

10.0

Zone

D. cuspidatus sp. nov.

Epoch/
Stage

D. cuspidatus sp. nov. (knb)

Age
(Ma)

de Kaenel et al.

D. kugleri Group

15.5
15.97

CN2

19.0
19.5

NN2

CN1c

20.0
20.44

20.5

Aquitanian

21.0
21.5
22.0

24.0
24.5

NN1

NP26

23.155

CN1b

LATE
Chattian

23.5

23.03

OLIGOCENE

22.5
23.0

CN1a
24.15417.347
HRO17.609

D. druggii (>15 μ m)

NN3

EARLY

18.5

D. druggii (<10 μm )18.0

D. obtusus

17.178
HRO17.258

Burdigalian

17.5

MIOCENE

17.0

CN3

D. druggii (10-15 μm)

NN4

16.5

D. shumnykii sp. nov.

16.0

23.03022.757

D. druggii Group

NP25 CP19b

25.0

Figure 2: Range diagram of the Discoaster druggii and D. kugleri groups. Ranges and new ages for the NN (Martini, 1971) and CN (Okada & Bukry,
1980) zonations are derived from calibrations in ODP Leg 154 core samples as well as the Gulf of Mexico

…Discoaster and Catinaster taxonomy and stratigraphy…

Discoaster obtusus Gartner, 1967
Pl. 3, figs 6–8
1967 Discoaster obtusus Gartner, p. 2, pl. 3, figs. 1–4,
5a–b, 6a–b
Remarks: The holotype (10μm) was recovered from sample Bo267 (Bolli, 1957), which has been placed in Zone
NN2. Discoaster obtusus has a hexagonal outline and very
short, pointed rays. Discoaster obtusus is a thicker form
with shorter and more pointed rays than D. shumnykii.
Occurrence: Discoaster obtusus ranges from Upper
Oligocene (NP26) to Upper Pliocene (NN18) in the Leg
154 material where it is dated from 24.154Ma (926B53X-4, 85–86cm; error 0.019Ma) to 2.286Ma (926C-7H-6,
114–116cm; error 0.024Ma). The range of this taxon is not
yet established in the GoM.
4.2 Discoaster kugleri group
The Discoaster kugleri group is characterized by taxa
with large, mostly featureless central areas and rays withsimple terminations. The group is comprised of three species distinguished by ray length, ray morphology (taperedor parallel-sided) and stratigraphic ranges. The presenceor absence of an indistinct central knob also has provento have stratigraphic significance and is used within thespecies. Like D. druggii, ray terminations can be pointed,
rounded, or truncate. Lateral nodes may also be present.
Martini & Bramlette (1963) illustrated three specimens of D. kugleri, each representing the three species
maintained herein. Their holotype (pl. 102, fig. 11) hasvery short, tapered rays with slightly notched tips; suchspecimens are referred to herein as D. kugleri. Their second specimen (pl. 102, fig. 12) has parallel-sided arms
resulting in angular inter-rays and is described herein as
D. hexapleuros. Such forms with hexagonal central area
peripheries reflect common usage in the GoM among thethree heritage companies. The presence or absence of a
distal knob on such hexagonal forms with parallel-sided
rays also have stratigraphic utility. Specimens with long,tapered rays (their plate 102, fig. 13) are described herein
as D. cuspidatus and represent both the origin and extinction of the group.
The entire D. kugleri group is illustrated on Plate 2
and the lineage on Figure 2. Discoaster cuspidatus andD. hexapleuros clearly predate D. kugleri, which marks
the base of Zone NN7 (=CN5b). The D. kugleri group isa stratigraphically-significant group with 13 coeval events
established among the three species and five morphotypes
in the GoM and Leg 154 (Table 1).
Discoaster kugleri Martini & Bramlette, 1963
Pl. 2, figs 1–10
1963 Discoaster kugleri Martini & Bramlette (pro parte),p. 853, pl. 102, fig. 11; non pl. 102, figs. 12–13
Remarks: The holotype of D. kugleri is 10.3μm with very
short, tapering rays and slightly indented ray terminations.
The central area is featureless (no knob) but with distinct

221

distal sutures. The ratio of free ray length to central area
size is normally from less than one-third for D. kugleri(0.20–0.31 ratio), but no higher than 0.40 (Pl. 2, figs 6–7).
Size = 8–15μm.
Occurrence: The LO of D. kugleri marks the base ofZone NN7 in the upper Middle Miocene and is dated at
11.910Ma (Table 1). The HO of D. kugleri was observed
in uppermost NN7, dated at 11.509Ma (Table 1). The LCO
and HCO of D. kugleri, as well as its acme, also havestratigraphic utility in Zone NN7 (Table 1).
Discoaster hexapleuros de Kaenel & Bergen, sp. nov.
Pl. 2, figs 11–20
1963 Discoaster kugleri Martini & Bramlette (pro parte),p. 853, pl. 102, fig. 12; non pl. 102, figs. 11, 13
Derivation of name: From Greek hexa, meaning six andpleuros, meaning side
Diagnosis: A late Middle to early Late Miocene Discoaster species having a large featureless central area
(a low relief knob may be present) and parallel-sided rays
with a corresponding hexagonal central area periphery.
Description: A small to medium-sized Discoasterwith a large hexagonal central area and parallel-sided rays.
The distal face of the central area is flat, usually featureless. A low-relief knob may be present. On the proximal
face of the central area, strong ridges run the length of therays and may meet in the center of the asterolith. The rayterminations are normally indented (“notched”). Lateral
nodes may be present. Ray length is variable, with free raylength to central area ratios around one-half (0.44–0.53 on
five measured specimens). Size = 7–15μm.
Remarks: Discoaster hexapleuros is distinguishedfrom D. cuspidatus by its parallel-sided rays. Discoasterkugleri has short to very short tapering rays. Discoasterhexapleuros has been referred to as “D. kugleri” in the
GoM by all three heritage companies.
Holotype dimension: 10.0#m
Holotype: Pl. 2, figs 11–13
Type locality: South Trinidad, Bolli (1957)
Type level: Sample Bo355, Globorotalia fohsi robusta
Zone, Cipero Formation, Zone NN7
Occurrence: The presence or absence of a central knob
has demonstrated stratigraphic utility in both the GoM
and Leg 154 research. The successive downhole HOs of
D. hexapleuros (knob) and D. hexapleuros are long-standing BP GoM markers, dated at 11.155Ma and 11.531Ma
in the Leg 154 research (Table 1). The LO of D. hexapleuros (knob) is dated at 12.186Ma and predates the LO of
D. hexapleuros at 11.962Ma (Table 1). Discoaster hexapleuros (knob) has been referred to as “D. cf. kugleri(knob)” in the BP GoM lexicon.
Discoaster cuspidatus de Kaenel & Bergen, sp. nov.
Pl. 2, figs 21–30
1963 Discoaster kugleri Martini & Bramlette (pro parte),p. 853, pl. 102, fig. 13; non pl. 102, figs. 11–12

222

de Kaenel et al.

Derivation of name: From Latin cuspidatus, meaning to
make pointed
Diagnosis: A Middle to early Late Miocene Discoasterspecies having a featureless central area (a low relief knob
may be present) and six long, tapering rays.
Description: A small to medium-sized Discoasterspecies with a large featureless central area and relatively
long, tapering rays. The distal face of the central area isflat, usually featureless. A low-relief knob may be present.
On the proximal face of the central area, strong ridges run
the length of the rays and may meet at the center of theasterolith. The ray terminations may be rounded, pointed
or indented. Lateral nodes may be present. The ratio of thefree ray length to central area varies between 0.45–0.80(8 measured specimens). Size = 8–15μm.
Remarks: Martini & Bramlette (1963) stated that“some specimens show a very small central knob andweak ridges extending along the rays to one side of themedian line” (p. 853). We noted specimens with a low
relief distal knob (Pl. 2, fig. 25) as D. cuspidatus (knob).
Discoaster cuspidatus is distinguished from D. kugleri
by its free ray length and from D. hexapleuros by its
tapered rays. Discoaster cuspidatus has been referred toas “D. cf. kugleri (taper)” in the BP GoM lexicon.
Holotype dimension: 11.6μm
Holotype: Pl. 2, figs 21–22
Type locality: South Trinidad, Bolli (1957)
Type level: Sample Bo355, Globorotalia fohsi robusta
Zone, Cipero Formation, Zone NN7
Occurrence: Discoaster cuspidatus ranges from
the Middle Miocene to early Late Miocene, dated from
13.217Ma to 11.037Ma (Table 1, Figure 2). The HO of
D. cuspidatus marks a prominent stratigraphic horizon in
the GoM, together with the HO of D. emblematicus andHO of D. ulnatus (Table 1) The LRO of the D. cuspidatus
has also been utilized in GoM wells and dated at 12.968Ma
in the Leg 154 research (Table 1). We have determined thesame extinction levels for morphotypes with and without
central knobs in the Leg 154 research, whereas the appearance of specimens with central knobs predate the appearance those without central knobs by approximately 190ky(Table 1).
4.3 Discoaster deflandrei group
This group is characterized by their complex, “wrenched”
bifurcations. Although it includes species with featureless central areas (Pl. 3, figs 9–22) exemplified by
D. deflandrei, these “wrenched” bifurcations differentiate them from the D. kugleri and D. druggii groups. The
D. deflandrei group also includes taxa with ornate central areas (Pl. 4, figs 1–10), as typified by D. saundersii.
The D. sanmiguelensis and D. musicus groups also haveornate central areas, but with different ray terminations. Eight taxa are included in the D. deflandrei group(Figure 3), including four new species and nine GoM
events (Table 1).

Discoaster leroyi de Kaenel & Bergen, sp. nov.
Pl. 3, figs 9–10
Derivation of name: In honor of former BP geologist
Andy Leroy (Houston, TX, USA)
Diagnosis: A five-rayed species of the D. deflandrei
group with a featureless central area.
Description: This five-rayed asterolith has flared,
symmetrically-arranged rays with broad, ‘wrench’-likebifurcations. The inter-ray areas are rounded, free rays are
medium length, and the central area is featureless.
Remarks: Discoaster leroyi is distinguished fromother members of the D. deflandrei group by having fiverays and a featureless central area.
Holotype dimension: 9.2#m
Holotype: Pl. 3, fig. 10
Type locality: ODP Leg 154, Hole 926A, Ceará Rise,
western equatorial Atlantic
Type level: Sample 926A-29-5, 80–82cm (13.613Ma),
Zone NN5
Occurrence: Discoaster leroyi ranges from the Lower
Eocene (NP10) to the Middle Miocene (NN7), which isdated at 11.794Ma (Sample 926A-26H-4, 37–39cm; error
0.019Ma). The HRO of D. leroyi is a GoM marker, dated
at 15.379Ma (Table 1).
Discoaster salomonii de Kaenel & Bergen, sp. nov.
Pl. 3, figs 11–12, 17
1954 Discoaster deflandrei Bramlette & Riedel (pro parte),p. 399, text fig. 1c; non pl. 39, fig. 6, text figs. 1a, 1b
Derivation of name: In memory of nannofossil biostratigrapher Ralph Salomon and former Amoco colleague(Houston, TX, USA)
Diagnosis: A six-rayed Discoaster species having afeatureless central area and broad, ‘wrench’-like bifurcate
rays with circular inter-ray areas.
Description: A medium-sized asterolith with six,
short rays that taper and then flare distally to form broad‘wrench’-like bifurcations. The large central area is featureless, and the ray sutures are distinct. The ray lengthand morphology combine to form diagnostic circularinter-ray areas.
Remarks: Discoaster salomonii is equivalent to theconcept of D. calculosus employed by Amoco in the GoM.
As used by BP, D. calculosus is a larger form (15μm) withmuch shorter free ray length, forming broad and shallow
inter-ray areas.
Holotype dimension: 9.6#m
Holotype: Pl. 3, figs 11–12
Type locality: South Trinidad, Bolli (1957)
Type level: Sample Bo267, Catapsydrax dissimilis
Zone, Cipero Formation, Zone NN2
Occurrence: Historically, the HO of D. salomonii has
been used as GoM marker by Amoco and post-merger
BP. This event has been dated in the Leg 154 research at
15.098Ma (Table 1). The species ranges into the Lower
Oligocene.

…Discoaster and Catinaster taxonomy and stratigraphy…

Epoch/
Stage

10.0

LATE
Tortonian

CN7b
CN7a

NN8

CN6

NN7

CN5b

NN6

CN5a

NN5

CN4

?
11.037

11.63

Serravallian

12.5

MIDDLE

13.0
13.5
14.0

15.0

15.97

NN4

18.0
18.5

CN2

EARLY

NN3

19.0
19.5
20.0

20.44

20.5

NN2

CN1c

Aquitanian

21.0
21.5
22.0

inc14.320
15.098
HRO15.379

HCO16.537

HAO17.456
18.05318.132D. leroyi sp. nov.

17.5

CN3

Burdigalian

17.0

MIOCENE

16.5

D. nephados

15.5
16.0

11.794

13.82

Langhian

14.5

HRO11.575

D. deflandrei

12.0

D. deflandrei Group

?

18.852

D. durioi
sp. nov.

11.5

NN9

D. calculosus

11.0

Okada
Martini & Bukry(1971) (1980)

D. salomonii sp. nov.

10.5

Zone

D. emblematicus sp. nov.

Age
(Ma)

223

24.0
24.5

NN1

NP26

D. saundersii

23.5

23.03

CN1b

LATE
Chattian

23.0

OLIGOCENE

22.5

CN1a
NP25 CP19b?

24.40824.30425.0

Figure 3: Range diagram of the Discoaster deflandrei group. Ranges and new ages for the NN (Martini, 1971) and CN (Okada & Bukry, 1980) zonations are derived from calibrations in ODP Leg 154 core samples as well as the Gulf of Mexico

224

de Kaenel et al.

Discoaster nephados Hay, 1967
Pl. 3, fig. 13
1967 Discoaster nephados Hay in Hay, Mohler, Roth,Schmidt & Boudreaux, p. 452, pl. 2, figs. 4–5
Remarks: Discoaster nephados is a medium-sized Discoaster with short, flaring rays and very broad, wrench-likebifurcations; the central area is featureless. The space between
bifurcations is very narrow, as the bifurcations almost touch.
Occurrence: Discoaster nephados ranges from Upper
Oligocene (upper NP25) to Upper Miocene (lower NN9).
Discoaster deflandrei Bramlette & Riedel, 1954
Pl. 3, figs 14–16
1954 Discoaster deflandrei Bramlette & Riedel (pro parte),p. 399, pl. 39, fig. 6, text fig. 1b; non text figs. 1a, 1c
Remarks: Discoaster deflandrei is reserved for six-rayedspecimens with flat, medium-sized central areas that arefeatureless. The rays flare and terminate in broad, ‘wrench’like bifurcations. The inter-ray area is subcircular. Very rare
specimens with three, four and seven rays are identified
as variants of D. deflandrei. Discoaster leroyi is describedherein for five-rayed D. deflandrei because of the demonstrated stratigraphic utility. Discoaster emblematicus is distinguished from D. deflandrei by its ornate central area.
Occurrence: Discoaster deflandrei ranges fromthe Lower Eocene (NP10) to Upper Miocene. The HO
is a long-standing BP marker in the GoM and dated at
11.575Ma on the HRO in the Leg 154 research (Table 1).
Downhole increases in this species have been utilized as
markers in the GoM by several workers; three such events
have been calibrated to the BP scheme in the Leg 154
materials (Table 1).
Discoaster calculosus Bukry, 1971
Pl. 3, figs 18–22
1971 Discoaster calculosus Bukry, p. 46, pl. 2, figs. 7–9
Remarks: This large Discoaster has broad and shallow
inter-ray areas. The holotype of D. calculosus is 15μm.
Bukry (1971) gave a size range of 11–21μm for the species. Its shallow inter-ray area distinguishes it from othermembers of the D. deflandrei group.
Occurrence: Discoaster calculosus is a long-standing
BP GoM marker and reserved for large specimens
bUD@μm). The HO is a GoM marker dated at 18.132Ma(Table 1). In Leg 154, the LO of the species is in Zone
NP25 and dated at 24.408Ma (Sample 926B-54X-3,
30–31cm; error 0.048Ma).
Discoaster saundersii Hay, 1967
Pl. 4, figs 1–3
1967 Discoaster saundersi Hay in Hay, Mohler, Roth,Schmidt & Boudreaux, p. 453, pl. 3, figs. 2–6
Remarks: Discoaster saundersii is a small to mediumsized Discoaster with a relatively small central area.
Hay et al., (1967) described the central disk as featureless;however, their illustrated specimens appear to have ornate

central areas, and this concept has been maintained in the
GoM for decades. Discoaster saundersii has the most idealized “wrenched” bifurcations of the D. deflandrei group.
The lower bifurcation pair is orthogonal to the ray orientation; the upper bifurcation pair roughly parallels the rays
(i.e., perpendicular to the lower pair). The angular natureof its bifurcation pairs (i.e., orthogonal) distinguishes
D. saundersii from both D. durioi and D. emblematicus.
Occurrence: The HO of D. saundersii is a GoM
marker in the Lower Miocene (lower NN3) and dated at
18.852Ma (Table 1). Hay et al., (1967) reported the LO of
D. saundersii in the Lower Oligocene (Globigerina ampliapertura Zone, NP23). We did not observe D. saundersii
below the uppermost Oligocene (NP25) in Leg 154, placing the LO in Sample 926B-54X-1, 60–61cm (24.304Ma;
error 0.022Ma).
Discoaster durioi de Kaenel & Bergen, sp. nov.
Pl. 4, figs 4–5
Derivation of name: In honor of GoM operations geologist Mark Durio (Houston, TX, USA)
Diagnosis: A six-rayed Discoaster with broadly angular, ‘wrench’-like bifurcations and an ornate central area.
The inner angle of the bifurcations is obtuse.
Description: A medium-sized Discoaster species,
normally with six rays that are short to medium length.
Free ray length is roughly equal to the central area width.
The bifurcations are broad and ‘wrench’-like (i.e., composed of paired elements). The lower bifurcation pairis orthogonal to the ray orientation. The upper bifurcation pair forms a low angle to the perpendicular of theray orientation; its inner bifurcation angle is obtuse. The
medium-sized central area has a prominent distal stellate stem surrounded by pitted depressions. The inter-ray
areas are subcircular.
Remarks: Discoaster durioi is distinguished fromD. saundersii by the obtuse angle formed by the upper
bifurcation pair. Discoaster durioi has been referred to as“D. aff. saundersii” in the BP GoM lexicon.
Holotype dimension: 10.8#m
Holotype: Pl. 4, fig. 4Type locality: South Trinidad, Bolli (1957)
Type level: Sample Bo267, Catapsydrax dissimilis
Zone, Cipero Formation, Zone NN2
Occurrence: The HO of D. durioi has been associated with a stratigraphic horizon marked by the HRO of
S. belemnos in six deep-water GoM wells. This stratigraphic horizon in upper Zone NN3 has been dated at
17.831Ma (Bergen et al., 2017; this volume). Discoaster
durioi was observed in samples from Zone NN3 in the Leg
154 research, where the HO is dated at 18.053Ma (Sample
926B-35X-6, 95–97cm; error 0.020Ma).
Discoaster emblematicus de Kaenel & Bergen,sp. nov.
Pl. 4, figs 6–10

…Discoaster and Catinaster taxonomy and stratigraphy…

Derivation of name: From Greek emblema, meaningornament, inlaid work
Diagnosis: A six-rayed Discoaster with broadly
rounded, ‘wrench’-like bifurcations and an ornate central
area.
Description: A medium-sized Discoaster species normally with six rays that are short to medium length. Freeray length is generally less than the central area width. The
bifurcations are broad and wrench-like (i.e., composed ofpaired elements). Both upper and lower bifurcation pairs
form a low angle to the perpendicular of the ray orientation. The medium to large central area has a prominentstellate distal stem surrounded by pitted depressions, giving the species its ornate central character.
Remarks: Discoaster emblematicus is differentiatedfrom D. deflandrei by its ornate central area. In both D. saundersii and D. durioi, the lower bifurcation pair is perpendicular to the ray orientation. Discoaster emblematicus has beenreferred to as “D. deflandrei (ornate)” in the BP GoM lexicon.
Holotype dimension: 10.0#m
Holotype: Pl. 4, fig. 6
Type locality: ODP Leg 154, Hole 926A, Ceará Rise,
western equatorial Atlantic
Type level: Sample 926A-27-1, 131–133cm (12.173Ma),
Zone NN6
Occurrence: The base of D. emblematicus has been
observed in the GoM and Leg 154 within the Lower Miocene. The HO is a GoM marker within lowermost Upper
Miocene (upper NN8) and dated at 11.037Ma (Table 1).
4.4 Discoaster sanmiguelensis group
This group is distinguished morphologically by its narrow
and rounded bifurcations (i.e. clubbed) and ornate central
areas. The ornate central area contains both a large, distal,stellate stem surrounded by pitted depressions and a small
proximal knob. The elements of the stellate stem project
between the rays but do not reach near the central area
periphery (unlike the D. musicus group).
The total range of the D. sanmiguelensis group, represented by D. ulnatus, is from upper Zone NN3 to upper
Zone NN8. This extinction is coincident with the extinctions of both the D. kugleri group and “ornate” D. deflandrei
group members and is dated at 11.037Ma. Three species
are placed in the D. sanmiguelensis group including two
new species, D. patulus and D. ulnatus. All three species
were included within the original concept of D. sanmiguelensis by Bukry (1981), who illustrated 13 specimens. The
appearance of D. ulnatus was followed shortly afterward by
D. patulus and then by D. sanmiguelensis; their extinctions
occurred in reverse order and are all deep-water GoM markers calibrated in the Leg 154 research (Table 1; Figure 4).
Discoaster patulus de Kaenel & Bergen, sp. nov.
Pl. 4, figs 11–14
1981 Discoaster sanmiguelensis Bukry (pro parte), p. 462,
pl. 2, fig. 9; non pl. 2, figs. 7–8, 10; pl. 3, figs. 1–14

225

Derivation of name: From Latin patulus, meaning open,
spread out
Diagnosis: A species of the D. sanmiguelensis groupwith rays that taper and then flare to form clubbed terminations.
Description: A small to medium-sized Discoasterspecies with a large ornate central area and relatively shortrays. The free rays taper strongly and then flare to form
narrow, thick bifurcations with rounded peripheries. The
central area width is greater than the length of the freerays. A stellate, distal stem projects between the rays anddoes not reach the central area periphery; pitted depressions surround this stellate stem. Size = 8–13#m.
Remarks: Discoaster sanmiguelensis has parallelsided rays and a hexagonal central area periphery,
whereas D. ulnatus has longer, tapered rays. Discoasteremblematicus is distinguished from D. patulus by its
broad (versus narrow) bifurcations. Discoaster patulus
has been referred to as “D. cf. sanmiguelensis” in the BP
GoM lexicon.
Holotype dimension: 9.6#m
Holotype: Pl. 4, figs 13–14
Type locality: ODP Leg 154, Hole 926A, Ceará Rise,
western equatorial Atlantic
Type level: Sample 926A-27-4, 13.5–15.5cm(12.368Ma), Zone NN6
Occurrence: The HO of D. patulus marks the top of
a GoM stratigraphic horizon and is dated at 11.509Ma in
the Leg 154 research (Table 1). The LO of D. patulus has
been calibrated to a GoM stratigraphic horizon marked by
the HO of Helicosphaera mediterranea, which has been
dated at 17.425Ma (Boesiger et al., 2017; this volume).
In the Leg 154 research, the species ranges sporadicallydown to Sample 928B-27X-CC. 30–32cm (17.347Ma;
error 0.036Ma).
Discoaster ulnatus de Kaenel & Bergen, sp. nov.
Pl. 4, figs 16–19
1981 Discoaster sanmiguelensis Bukry (pro parte), p. 462,
pl. 2, fig. 7; pl. 3, figs. 1, 4–7, 11, 12; non pl. 2, figs. 8–10;
pl. 3, figs. 2, 3, 8–10, 13–14
Derivation of name: From Latin ulna, meaning forearmand atus, meaning having the nature of
Diagnosis: A species of the D. sanmiguelensis groupwith relatively long rays that taper to form clubbed terminations.
Description: A small to medium-sized Discoasterspecies with a large ornate central area and relatively longtapered rays. The free rays taper to form narrow bifurcations with rounded peripheries. The free ray length isabout equal to the central area width. A stellate, distal stem
projects between the rays and does not reach the central
area periphery; pitted depressions surround this stellate
stem. Size = 8–15μm.
Remarks: Discoaster ulnatus has the longest rays of thethree species placed in the Discoaster sanmiguelensis group.

226

13.5
14.0

16.0

CN5b

NN6

CN5a

Langhian

CN4

15.97

16.5

NN4

CN3

NN3

CN2

NN2

CN1c

12.125

HRO12.173

13.82

NN5

MIOCENE

11.84913.06713.74312.021

13.637

13.637

12.692

C. glenos sp. nov.

NN7

11.37911.509D. catinatus sp. nov.

MIDDLE

13.0

15.5

CN6

D. sanmiguelensis

Serravallian

12.5

15.0

NN8

10.85011.037

11.63

12.0

14.5

CN7a

D. gamberi sp. nov.

11.5

CN7b

D. patulus sp. nov.

11.0

NN9

D. virginianus

LATE
Tortonian

10.5

Okada

Martini & Bukry(1971) (1980)

D. carneyi sp. nov.

10.0

Zone

D. musicus

Epoch/
Stage

D. ulnatus sp. nov.

Age
(Ma)

de Kaenel et al.

?12.757

13.61314.497

D. musicus
Group

17.5
18.0
18.5

EARLY
Burdigalian

17.0

19.0

D. sanmiguelensis
Group

19.5
20.0

Figure 4: Range diagram of the Discoaster sanmiguelensis and D. musicus groups. Ranges and new ages for the NN (Martini, 1971) and CN (Okada& Bukry, 1980) zonations are derived from calibrations in ODP Leg 154 core samples as well as the Gulf of Mexico

The rays of D. patulus flare and those of D. sanmiguelensis
are parallel-sided. Discoaster patulus has been referred to as“D. aff. sanmiguelensis” in the BP GoM lexicon.
Holotype dimension: 11.2#m
Holotype: Pl. 4, figs 17–18
Type locality: South Trinidad, Bolli (1957)
Type level: Sample JS32, Globorotalia fohsi lobata
Zone, Cipero Formation, Zone NN6
Occurrence: The HO of D. ulnatus is dated at
11.037Ma (Table 1); its marks a prominent GoM stratigraphic horizon along with the HO of D. emblematicus
and HO of D. cuspidatus. The LO of D. ulnatus is associated with a GoM stratigraphic horizon in uppermost
Zone NN3 marked by a flood of very small Reticulofenestra in four deep-water GoM wells; this horizon has
been dated at 17.713Ma (Sample 928B-28X-5, 30–31cm;
error 0.021Ma) in the Leg 154 research. The LO of theD. ulnatus has been placed in Sample 928B-28X-5, 65–67cm(17.731Ma; error 0.021Ma) in the Leg 154 research.
Discoaster sanmiguelensis Bukry, 1981
Pl. 4, figs 15, 20
1981 Discoaster sanmiguelensis Bukry (pro parte), p. 462,
pl. 2, figs. 8, 10; pl. 3, figs. 2, 3, 8–10, 13–14; non pl. 2,
figs. 7, 9; pl. 3, figs. 1, 4–7, 11, 12
Remarks: The light photographs of D. sanmiguelensis
illustrated by Bukry (1981) encompass what we consider the D. sanmiguelensis group herein. The holotype(10.2μm) has parallel-sided rays that form angular interray areas, resulting in a hexagonal central area periphery(upon focus). A stellate, distal stem projects between therays and does not reach the central area periphery. The
size range for this species is between 7–15#m. Discoastersanmiguelensis is distinguished from D. patulus and…Discoaster and Catinaster taxonomy and stratigraphy…

D. ulnatus by its parallel-sided rays and hexagonal central
area periphery.
Occurrence: The LO of D. sanmiguelensis has beencalibrated to the LO of D. petaliformis in several deepwater GoM wells. In Leg 154, the LO of D. sanmiguelensis
is dated at 15.617Ma (Sample 925D-37H-1, 140–141cm;
error 0.020Ma). Both the HO (11.849Ma) and the HRO(12.173Ma) of D. sanmiguelensis are GoM markers calibrated to the Leg 154 research (Table 1).
4.5 Discoaster musicus group
Discoaster musicus and D. sanmiguelensis are both characterized by parallel-sided rays, resulting in a hexagonal
central area periphery, and narrow, rounded bifurcations.
Discoaster musicus appeared about 1.1 million years
after D. sanmiguelensis, its likely ancestor. Discoastermusicus differs from D. sanmiguelensis only by the extension of its distal stellate stem to the central area periphery. The D. musicus group is characterized herein by thisextended distal stem (convex side of the asterolith). Ray
morphology distinguishes the five species included inthis group; three new species are described (Figure 4).
The evolution of the group is well constrained in the Leg
154 research (Figure 4), involving: the thinning of rays
(D. carneyi), elimination of the bifurcation (D. virginianus), shortening of the pointed ray (D. gamberi), andelimination of rays (D. catinatus). The species are arranged
from the bottom of Plate 4 (D. musicus) to the middle ofPlate 5 (D. catinatus) to reflect this evolution. Only thestratigraphic range of D. musicus is well constrained inboth the GoM and Leg 154 research (Table 1).
Discoaster musicus Stradner, 1959
Pl. 4, figs 21–25
1959 Discoaster musicus Stradner, p. 1088, fig. 28
1961 Discoaster musicus Stradner 1959; Stradner in Stradner & Papp (pro parte), p. 85, pl. 17, figs. 7a–b, 8a–b, 10;
text fig. 8/22; non pl. 17, figs. 4a–b, 5a–b, 9a–b; pl. 18,
figs. 2a–b
2010 Discoaster musicus Stradner 1959; in Stradner,
Aubry & Bonnemaison, p. 17, text figs. 9a–b
Remarks: The holotype of D. musicus from Stradner(1959) are two drawings (proximal and distal sides).
Stradner et al., (2010) re-illustrated the holotype drawings(text fig. 9a), along with four light photomicrographs ofthe holotype (text fig. 9b). The holotype has a hexagonal
central periphery and parallel-sided rays. Stradner et al.,(2010) also described that: (1) “the tips of large central staron the concave face can be seen as extra interstitial corners of the central disc” - the star reaches the central area
periphery; and (2) the convex face “can be decorated by anadditional star”. The holotype of D. musicus corresponds
to two specimens illustrated on Plate 4 (figs 21–24); thethird specimen illustrated on Plate 4 (fig 25) is considered transitional because the rays taper and the central
area periphery is not hexagonal. The type locality for the227

species is Frättingsdorf, Austria. Stradner & Papp (1961)
stated that the type level is lower Tortonian. We have somedoubt about this age assignment, as the type material also
contains planktonic foraminifera (P. glomerosa, G. bisphaericus and O. suturalis) indicative of the Langhianand lower Zone NN5. Discoaster musicus is distinguishedfrom other species of Discoaster with large hexagonal
central area peripheries by its prominent stellate stem that
extends to the edge of the central area between the parallel-sided rays.
Occurrence: The HO of D. musicus is a GoM marker
calibrated to the Leg 154 research and dated at 13.067Ma(Table 1). The LO of D. musicus has been associated withthe base acme Cyclicargolithus bukryi and basal Zone
NN5 (see Boesiger et al., 2017; this volume) in multiple
deep-water GoM wells. In Leg 154, the LO of D. musicus has been observed in lower Zone NN5 and dated
at 14.497Ma (Table 1). Discoaster musicus has been
observed down into Zone NN4 in three deep-water wells,
but these occurrences are believed to be transitional specimens with tapered rays.
Discoaster carneyi de Kaenel & Bergen, sp. nov.
Pl. 4, figs 26–30
1993 Discoaster sp. cf. musicus, Aubry, p. 364, pl. 3,
figs. 9–10
Derivation of name: In honor of foraminifera specialist James “Chip” Carney, former BP-Amoco colleague(Houston, TX, USA)
Diagnosis: A species of the D. musicus group having
slender, tapered rays with simple bifurcations.
Description: A medium-sized Discoaster species withthin, slender rays which taper and then flare to form simple, delicate bifurcations. The large central area contains
a stellate distal stem which extends to the central area
periphery between the rays. Central area width and ray
length are approximately equal. A small proximal knob ispresent.
Remarks: Within the D. musicus group, D. carneyi
is distinguished by having thin, tapered rays with simple
bifurcations. The delicate nature of these bifurcations canmake D. carneyi difficult to distinguish from D. gamberiand D. virginianus in poorly-preserved material; those two
species have thinly pointed rays. Discoaster musicus has
wider, parallel-sided free rays with clubbed terminations.
Discoaster carneyi has been referred to as “D. musicus(delicate)” in the BP GoM lexicon.
Holotype dimension: 9.2#m
Holotype: Pl. 4, figs 26–27
Type locality: ODP Leg 154, Hole 926A, Ceará Rise,
western equatorial Atlantic
Type level: Sample 926A-29-4, 19–21cm (13.499Ma),
Zone NN5
Occurrence: Discoaster carneyi ranges from upper
Zone NN5 (926A-29H-7, 2.4–4.4cm) to upper Zone NN6(Sample 926A-27H-1, 22–24cm) in the Leg 154 research,

228

de Kaenel et al.

dated from 13.743Ma (error 0.013Ma) to 12.125Ma (error
0.072Ma). The stratigraphic range of D. carneyi is notwell established in the GoM. The HO of D. carneyi has
been observed in basal to middle Zone NN6 in six wells,
whereas the LO has been noted in upper Zone NN5 in asingle deep-water GoM well.
Discoaster virginianus (Self-Trail, 2014) de Kaenel &Bergen, emended, comb. nov.
Pl. 5, figs 1–4
1993 Catinaster sp., Aubry, p. 364, pl. 3, figs. 13–15
2014 Catinaster virginianus Self-Trail (pro parte), p. 53,
pl. 2, fig. 1; non pl. 1, figs. 1–12; pl. 2, figs. 2a–b
Emended diagnosis: A small to medium-sized Discoasterspecies with delicate long, pointed rays. On the distal side,a thick stellate stem extends to the periphery of the central
area between the rays. A proximal knob is present.
Remarks: The holotype of C. virginianus is re-illustrated on Plate 5 (fig. 1). This specimen has thin, pointed
rays and a stellate stem that extends to the central area
periphery. The species is transferred to the genus Discoaster. The holotype takes precedence over the diagnosis
and description; it is considered a different species than
all other specimens illustrated by Self Trail (2014), which
represent three species described herein. The slender rays
are not to be confused with spines. Discoaster virginianus
has been referred to as “D. musicus (pointed)” and lateras “D. gamberi” in the BP GoM lexicon. These two taxa
were not differentiated within BP GoM well analyses until
recently. It is differentiated from D. gamberi herein byhaving longer rays.
Occurrence: Discoaster virginianus ranges fromupper Zone NN5 (926A-29H-5, 125–127cm) to upper
Zone NN6 (Sample 926A-26H-6, 125–127cm) in the
Leg 154 research, dated from 13.637Ma (error 0.011Ma)
to 12.021Ma (error 0.018Ma). Discoaster virginianus(D. musicus “pointed”) ranges from upper Zone NN4 tomiddle Zone NN6, as established in four deep-water GoM
wells and includes the concept of another species withpointed ray terminations (D. gamberi). The range of Zone
NN5 to Zone NN8 for D. virginianus given by Self-Trail(2014) is not applicable to our restricted and emended
concept of the species.
Discoaster gamberi de Kaenel & Bergen, sp. nov.
Pl. 5, figs 5–10
1993 Catinaster sp., Aubry, p. 364, pl. 3, figs. 17–19
2008 Catinaster sp. “A”, Denne, p. 239, pl. 2, fig. 5a; nonpl. 2, fig. 5b2014 Catinaster virginianus, Self-Trail, p. 53, pl. 1, figs.
1–2; non pl. 1, figs. 3–12; pl. 2, figs. 1–2
Derivation of name: In honor of foraminifera specialist
James Gamber, former BP-Amoco colleague (Houston,
TX, USA)
Diagnosis: A species of the D. musicus group withshort, slender rays which taper to points.

Description: A small to medium-sized Discoasterspecies with very short pointed rays. The large central area
contains a stellate distal stem which extends to the central area periphery between the rays. Central area widthis much greater than ray length. A small proximal knob ispresent.
Remarks: Discoaster gamberi is distinguished fromD. virginianus by its shorter rays and D. catinatus by thepresence of very short rays. Discoaster gamberi has beenreferred to as D. brevigamberi in the BP GoM lexicon andearlier within the concept of “D. musicus (delicate)”. This
early concept also included the other species with pointedrays, D. virginianus.
Holotype dimension: 6#mHolotype: Pl. 5, figs 9–10
Type locality: ODP Leg 154, Hole 926A, Ceará Rise,
western equatorial Atlantic
Type level: Sample 926A-29H-2, 141–143cm(13.429Ma), Zone NN5
Occurrence: Discoaster gamberi ranges from upper
Zone NN5 (926A-29H-5, 125–127cm) to lower Zone
NN8 (Sample 926B-25H-6, 113–115cm) in the Leg
154 research, dated from 13.637Ma (error 0.011Ma) to
11.379Ma (error 0.024Ma). The stratigraphic range ofD. gamberi is poorly established in the GoM. The HO of
D. gamberi has been associated with the HO of D. deflandrei in only one BP GoM deep-water exploration well; thisstratigraphic horizon in uppermost Zone NN7 has been
dated at 11.575Ma (Table 1).
Discoaster catinatus de Kaenel & Bergen, sp. nov.
Pl. 5, figs 11–20
2008 Catinaster sp. “A”, Denne (pro parte), p. 239, pl. 2,
fig. 5b; non pl. 2, fig. 5a2014 Catinaster virginianus Self-Trail (pro parte), p. 53,
pl. 1, figs. 3–12; non pl. 1, figs. 1–2; pl. 2, figs. 1–2
Derivation of name: From Latin catinus, meaning deep
vessel, pot
Diagnosis: A species of the D. musicus group with aserrate periphery and no rays.
Description: A small to medium-sized Discoasterspecies without rays. The serrate central area periphery isrounded. It contains a stellate distal stem which extends tothe central area periphery. A thick proximal knob is present.
Remarks: Discoaster catinatus does not have the typical basket-like structure of the genus Catinaster, but has athick proximal knob typical of Discoaster. It may be transitional between the two genera. The absence of rays distinguishes it from other members of the D. musicus group.
Discoaster catinatus has been referred to as “D. musicus(serrate)” in the BP GoM lexicon. All four specimens
illustrated herein were recovered from the same sample.
Holotype dimension: 6.8#m
Holotype: Pl. 5, figs 16–18
Type locality: ODP Leg 154, Hole 926A, Ceará Rise,
western equatorial Atlantic

…Discoaster and Catinaster taxonomy and stratigraphy…

Type level: Sample 926A-29-5, 80–82cm (13.613Ma),
Zone NN5
Occurrence: Discoaster catinatus ranges from upper
Zone NN5 (926A-29H-5, 80–82cm) to middle Zone
NN6 (Sample 926A-27H-6, 138–140cm) in the Leg
154 research, dated from 13.613Ma (error 0.024Ma) to
12.692Ma (error 0.031Ma). The HO of D. catinatus has
been associated with the HRO of D. sanmiguelensis infour deep-water GoM wells. This stratigraphic horizon
in upper Zone NN6 has been dated at 12.173Ma (Table1). The LO has been observed in upper Zone NN5 inproximity to the HO of D. petaliformis (Table 1) in three
deep-water GoM wells.
4.6 Discoaster micros group
This group is characterized by “flat” ray bifurcations andranges from upper Zone NN4 to Zone NN9 (Figure 5).
The Discoaster micros group includes six species, four ofwhich are described as new. The two described species,
D. micros and D. transitus, have featureless central areas
and the youngest extinctions within the group. The two
new species with featureless central areas, D. arneyi andD. premicros, are the two oldest representatives of thegroup; the stratigraphic ranges of these two closely-related species are well-utilized in the GoM framework andcalibrated to the Leg 154 research (Table 1). The remaining two new species, D. catillomicros and D. stellimicros,
have ornate central areas and bridge the stratigraphic gap
between the other two pairs of species. The older andyounger pairs of species are each differentiated morphologically by their free ray length.
Discoaster premicros de Kaenel & Bergen, sp. nov.
Pl. 5, figs 21–23
2008 Discoaster cf. D. lidzi, Denne, p. 238, pl. 1, fig. 4
Derivation of name: From Latin prae, meaning, before;
from Greek mikros, meaning small, little
Diagnosis: A thick species of the D. micros group withshort rays, flat bifurcations and a featureless central area.
Description: A small, thick Discoaster species with
six very short, flaring rays that terminate in obtuse bifurcations that are nearly orthogonal to the ray direction. The
rays are broad, and their length is less than the central
area width. The large central area is thick and devoid of
any structures. Specimens show distinct optical contrast
with the mounting medium (in plan light) due to their
thickness.
Remarks: Discoaster arneyi has longer rays andslightly lower ray bifurcation angles than D. premicros; it
is likely ancestral to D. premicros. Discoaster stellimicros
has a central stem. Discoaster premicros has been referred
to as “D. aff. micros” in the BP GoM lexicon.
Holotype dimension: 6.0#m
Holotype: Pl. 5, figs 21–22
Type locality: ODP Leg 154, Hole 925C, Ceará Rise,
western equatorial Atlantic

229

Type level: Sample 925C-35-3, 120–122cm (14.617Ma),
Zone NN5
Occurrence: Both the LO and HO of D. premicros are utilized in the GoM, dated at 15.498Ma (upper
NN4) and 14.189Ma (middle NN5), respectively, in the
Leg 154 research (Table 1). The HRO and first downhole increase (INC) in this Langhian species are alsoutilized as GoM markers in Zone NN5 and calibrated to
the Leg 154 research (Table 1). Denne (2008) noted thistaxon as a “flag” for Zone NN5.
Discoaster arneyi de Kaenel & Bergen, sp. nov.
Pl. 5, figs 24–25
Derivation of name: In honor of nannofossil paleontologist James Arney (Bugware Inc., Tallahassee, FL, USA)
Diagnosis: A thick species of the D. micros group withlong rays, nearly flat bifurcations and a featureless central
area.
Description: A thick, small to medium-sized species of Discoaster with six relatively long rays. The rays
flare slightly and terminate in simple bifurcations. The
ray bifurcations are broad and form an obtuse angle. Ray
length is greater than the central area width, and theirjunctures tend to be angular. The central area is thick anddevoid of any structures. Specimens show distinct opticalcontrast with the mounting medium (in plan light) due totheir thickness. Size ranges from 7–11#m.
Remarks: Discoaster premicros is another thick species from the D. micros group, but has much shorter freerays which terminate in flatter bifurcations. Discoasterdeflandrei has flared arms which terminate in more complex, ‘wrench’-like bifurcations. Discoaster arneyi has
been referred to as “small D. aff. deflandrei” in the BP
GoM lexicon.
Holotype dimension: 7.6#m
Holotype: Pl. 5, fig. 24
Type locality: MC 771, Mississippi Canyon, Gulf of
Mexico.
Type level: middle Zone NN5
Occurrence: Discoaster arneyi ranges nearly theentire Langhian. Both the LO and HO of D. arneyi are
utilized in the GoM, dated at 15.857Ma and 14.091Ma,
respectively, in the Leg 154 research (Table 1).
Discoaster stellimicros Pospichal & Bergen, sp. nov.
Pl. 5, figs 26–28
Derivation of name: From Latin stella, meaning star;
Greek mikros, meaning small, little
Diagnosis: A species of the D. micros group with shortrays, flat bifurcations and a stellate stem.
Description: A small Discoaster species with six short,tapering rays that flare and terminate in obtuse bifurcations
that are nearly orthogonal to the ray direction. Ray lengthis less than the central area width. The ray sutures are mostvisible on the distal side of the large central area. A proximal stellate stem is present and projects between the rays.

230

Epoch/
Stage

8.5

Zone
Martini(1971)

Okada &
Bukry
(1980)

CN8b

9.0

NN10

CN8a

D. micros Group

10.5

9.826
NN9

11.5

CN6

NN7

CN5b

NN6

CN5a

17.0

D. stellimicros
sp. nov.

Serravallian

11.589?12.82113.067

NN5

CN4

15.97

NN4

14.091

D. premicros sp. nov.

13.82

14.189
HRO-14.397
inc-14.539

15.49815.857CN3

EARLY
Burdig.

16.5

11.50913.35015.5
16.0

11.509

D. arneyi sp. nov.

15.0

NN8

Langhian

14.5

MIDDLE

14.0

MIOCENE

13.5

10.379

11.63

12.0

13.0

CN7b

CN7a

11.0

12.5

10.082

D. micros

10.0

D. catillomicros sp. nov.

LATE
Tortonian

9.5

D. transitus

Age
(Ma)

de Kaenel et al.

Overlapping GoM/Leg 154 range
Extended GoM range

17.5
Figure 5: Range diagram of the Discoaster micros group. Ranges and new ages for the NN (Martini, 1971) and CN (Okada & Bukry, 1980) zonations
are derived from calibrations in ODP Leg 154 core samples as well as the Gulf of Mexico

Remarks: Discoaster stellimicros differs fromD. premicros by having a prominent stellate stem. Discoaster catillomicros also has a stellate stem and short,flat rays but is distinguished by its deep central area
depressions. Discoaster stellimicros has been referred
to as “D. micros (star)” in the BP GoM lexicon.
Holotype dimension: 7.6#m
Holotype: Pl. 5, figs 27–28
Type locality: ODP Leg 154, Hole 926A, Ceará Rise,
western equatorial Atlantic
Type level: Sample 926A-27-7, 11.5–13.5cm(12.710Ma), Zone NN6
Occurrence: Discoaster stellimicros ranges fromlower Zone NN6 (926A-29H-1, 100–102cm) to lowermost
Zone NN8 (Sample 926A-26H-2, 26.5–28.5cm) in the
Leg 154 research, dated from 13.350Ma (error 0.010Ma)

to 11.509Ma (error 0.019Ma). The HO of D. stellimicros
has been associated with the HO of Discoaster deflandrei
in a single BP GoM well; this stratigraphic horizon in
upper Zone NN7 has been dated at 11.575Ma (Table 1).
Discoaster transitus Peleo-Alampay, Bukry, Liu &Young, 1998
Pl. 5, figs 29–30
1998 Discoaster transitus Peleo-Alampay, Bukry, Liu &Young, p. 82, pl. 2, figs. 9–11
Remarks: Discoaster transitus is a small to medium-sized
Discoaster with a small central area without the distinctive
knob and flaring rays that terminate in flat bifurcations.
The tips of the bifurcations are close to each other but do
not fuse. Discoaster micros has shorter rays and a relatively larger central area than D. transitus. Peleo-Alampay

…Discoaster and Catinaster taxonomy and stratigraphy…

et al., (1998) suggested Discoaster transitus as ancestral
to Catinaster, but other ancestors are possible.
Occurrence: In Leg 154, D. transitus is sporadic in
occurrence from Sample 926A-26H-2, 117.5–119.5cm inuppermost Zone NN7 (11.589Ma; error 0.036Ma) to Sample 926B-24H-5, 1–3cm in middle Zone NN9 (10.379Ma;
error 0.062Ma). The HO of D. transitus has been observed
at slightly higher stratigraphic levels in deep-water GoM
wells; this event has been associated with the HRO of
Catinaster coalitus in 9 wells. This stratigraphic horizon in upper Zone NN9 has been dated at 9.826Ma(Table 1).
Discoaster micros (Theodoridis, 1984) de Kaenel &Villa, 1996
Pl. 6, figs 1–6
1984 Eu-discoaster micros Theodoridis, p. 170, pl. 36,
figs. 1–3
1996 Discoaster micros (Theodoridis, 1984) de Kaenel &Villa, p. 124, pl. 6, figs. 9–10
Remarks: Discoaster micros is a small Discoaster witha large, featureless central area and very short bifurcate
rays. The bifurcations are flat or with a highly obtuse
angle (more than 120°). As with many Discoaster species,
the central area may have distinct proximal ridges. Discoaster micros is distinguished from D. catillomicros by
the absence of a central stem and from D. transitus by having shorter rays and a relatively larger central area. Discoaster premicros has the same morphology as D. micros
but is thicker and much older than D. micros.
Occurrence: The HO of D. micros is coeval in boththe GoM and Leg 154 research, where it has been dated in
the latter at 10.082Ma (Table 1). The LO of D. micros in
the GoM has been associated with the HRO of D. sanmiguelensis in three deep-water wells and the HRO of Calcidiscus premacintyrei in a single well. These two GoM
stratigraphic horizons in upper Zone NN6 have been dated
at 12.173Ma (Table 1) and 12.321Ma (Boesiger et al.,2017, this volume), respectively. In the Leg 154 research,the LO of the species was observed in mid-Zone NN6 anddated at 13.067Ma (Sample 926A-28H-4, 107.5–109.5cm;
error 0.013Ma).
Discoaster catillomicros de Kaenel & Bergen,sp. nov.
Pl. 6, figs 7–10
Derivation of name: From Latin catillus, meaning deep
vessel; Greek mikros, meaning small, little
Diagnosis: A species of the D. micros group with shortrays, flat bifurcations and central area depressions whichmimic the genus Catinaster.
Description: A small Discoaster species with six
short, tapering rays that terminate in obtuse bifurcations
that are nearly orthogonal to the ray direction. The rays
are broad and their length much less than the central area
width. Inter-ray areas are very shallow and rounded. A

231

stellate distal stem extends to the central area periphery
between the rays. Deep central area depressions are present around the stellate stem.
Remarks: Discoaster catillomicros is similar in sizeand shape to D. stellimicros, but differs by having large
central depressions that mimic some Catinaster species.
Discoaster catillomicros differs from Catinaster by having free rays. Discoaster catillomicros has been referred
to as “D. cf. micros (star)” and “Halfnaster” sp. in the BP
GoM lexicon.
Holotype dimension: 5.2μm
Holotype: Pl. 6, figs 7–8
Type locality: South Trinidad, Bolli (1957)
Type level: Sample Bo355, Globorotalia fohsi robusta
Zone, Cipero Formation, Zone NN7
Occurrence: The HO of D. catillomicros has been
associated with the HO of D. patulus in five deep-water
GoM wells; these two events in lower Zone NN8 arecoeval in the Leg 154 research, both dated at 11.509Ma(Table 1). A LO for the species has not yet been established in the GoM. In the Leg 154 research, the LO in midZone NN6 (Sample 926A-28H-1, 86–88cm; 12.821Ma;
error 0.019Ma) is not considered reliable.
4.7 Discoaster petaliformis group
The Discoaster petaliformis group includes an assortmentof species with high central stems and/or simple bifurcations. Five species are placed in this group (Figure 6),
including two new species (D. discissus and D. apetalus).
D. formosus is the only species without bifurcate rays but
has a high rounded stem. Discoaster discissus has the samehigh rounded stem, but with bifurcate rays. Discoaster
petaliformis is the only species utilized for GoM stratigraphy (Table 1). Discoaster signus and D. apetalus have no
proven stratigraphic utility in the GoM, but morphologies
similar to D. petaliformis.
Discoaster petaliformis Moshkovitch & Ehrlich, 1980
Pl. 7, figs 1–8
1980 Discoaster petaliformis Moshkovitch & Ehrlich, p. 17,
pl. 6, figs. 1–7
Remarks: Moshkovitz & Ehrlich (1980) illustrated three
specimens of D. petaliformis recovered from core taken
in a well located on the central coast of Israel. Two of
the specimens, including the holotype, were transferred
between the light and scanning electron microscopes.
All three specimens have high, stellate proximal stems
which project down the rays. The holotype has a larger
central area and more tapered rays than the other two
specimens, which have slender rays and very small centers filled by the stellate stem. These slender forms are
more typical of specimens recovered from GoM wells.
Discoaster signus has a similar morphology, but a verysmall central area filled only by a high, round knob. The
holotype of D.petaliformis has a low, round distal knob.
D. apetalus has no central projection.

232

10.0

LATE
Tortonian

10.5
11.0
11.5

D. petaliformis Group
10.996

CN7a
NN8

CN6

NN7

CN5b

NN6

CN5a

11.212
11.57514.0

13.49913.82

CN4Langhian

MIOCENE

NN5

15.97

?15.818NN4

16.5

12.790D. discissus sp. nov.

13.5

16.0

CN7b

D. signus

MIDDLE

13.0

15.5

NN9

13.877

13.637

D. petaliformis

Serravallian

12.5

15.0

Okada
Martini & Bukry(1971) (1980)

11.63

12.0

14.5

Zone

acme14.617

D. formosus

Epoch/
Stage

D. apetalus sp. nov.

Age
(Ma)

de Kaenel et al.

13.756?15.578
15.778

CN3

17.5
18.0
18.5

EARLY
Burdigalian

17.0

Overlapping GoM/Leg 154 range
NN3

CN2

Extended Leg 154 range

19.0
Figure 6: Range diagram of the Discoaster petaliformis group. Ranges and new ages for the NN (Martini, 1971) and CN (Okada & Bukry, 1980)
zonations are derived from calibrations in ODP Leg 154 core samples as well as the Gulf of Mexico

Occurrence: Both the HO and LO of D. petaliformis
are utilized in the GoM and dated from 15.778Ma to13.637Ma in the Leg 154 research (Table 1). The top acmeis also utilized as a GoM marker by BP and calibrated by
the Leg 154 research (Table 1).
Discoaster apetalus de Kaenel & Bergen, sp. nov.
Pl. 7, figs 9–11
Derivation of name: From Greek: a-, meaning not, without; and petalon, meaning leaf, petal
Diagnosis: A medium to large Discoaster having six
long, narrow rays with delicate bifurcations and verysmall central area with no projection.
Description: A medium to large Discoaster species with
six long bifurcate rays. The rays are narrow and are parallel-sided or taper slightly towards the bifurcations. The bifurcations are very thin, and the angle they form is variable. The
central area is very small. There is no central projection.

Remarks: Discoaster petaliformis and D. signus areother six-rayed Discoaster with morphologies similar to
D. apetalus, but both these species have central projections. Discoaster apetalus has been referred to as “D. petaliformis (no stem)” in the BP GoM lexicon.
Holotype dimension: 11.6#m
Holotype: Pl. 7, figs 9–10
Type locality: ODP Leg 154, Hole 926A, Ceará Rise,
western equatorial Atlantic
Type level: Sample 926A-29-4, 116–118cm(13.562Ma), Zone NN5
Occurrence: Discoaster apetalus was originally distinguished in the Leg 154 research during investigation of
the D. petaliformis extinction. The HO of D. apetalus iswell constrained upper Zone NN5 in the Leg 154 research(Sample 926A-29-4, 19–21cm) and dated at 13.499Ma(0.004Ma error), approximately 138ky younger thanthe extinction of D. petaliformis (Table 1). The top of

…Discoaster and Catinaster taxonomy and stratigraphy…

D. apetalus was sequenced above the HO of D. petaliformis in one western and two eastern deep-water GoM
wells. The LO of Discoaster apetalus is not well constrained.
It was observed persistently in Leg 154 samples down toSample 926A-29-7, 63–65cm (13.782Ma) within Zone NN5.
Definitive specimens were found as low as Sample 925C-381, 130–132cm (15.818Ma) within upper Zone NN4.
Discoaster signus Bukry, 1971
Pl. 7, figs 13–15
1971 Discoaster signus Bukry, p. 48, pl. 3, figs. 3–4
Remarks: Discoaster signus has no proven stratigraphic
utility in the GoM, but is included herein because of its
morphologic similarity to D. petaliformis. Discoastersignus has slender, long rays and delicate bifurcations.
Bukry (1971) described D. signus as having no developed
central area and a prominent knob present at the hub of
the rays. This knob cannot be seen on the holotype but isclear on the second specimen illustrated by Bukry (1971).
Discoaster petaliformis has a high stellate stem oriented
along its six slender rays, whereas D. apetalus has no central projection.
Occurrence: A stratigraphic range has not been established for D. signus in the GoM. A very distinct HO has been
established in the Leg 154 research; this event has been placed
within mid-Zone NN6 in Sample 926A-28H-1, 38–40cm(12.790Ma; error 0.033Ma). The LO is in upper Zone NN4.
Discoaster discissus de Kaenel & Bergen, sp. nov.
Pl. 7, figs 12, 16
Derivation of name: From Latin di, meaning two, in part;and scissus, meaning cut, split
Diagnosis: A medium to very large Discoaster with
six long tapering rays with narrow bifurcations and a relatively large central area containing a very high, roundknob.
Description: A medium to very large Discoasterspecies with a large central area and long, tapering bifurcate rays. The bifurcations are short and narrow. Free raylength is greater than the central area width. A very high,prominent knob is present and has a slightly stellate torounded outline.
Remarks: Discoaster discissus and D. formosus possess
the same high proximal knob, but D. discissus has bifurcate
rays. Large specimens of D. decorus have the same morphology as D. discissus, but lack the prominent knob. Discoasterdiscissus has been referred to as “D. formosus (bifurcate)” in
the BP GoM lexicon.
Holotype dimension: 24.0#m
Holotype: Pl. 7, fig. 12Type locality: ODP Leg 154, Hole 926A, Ceará Rise,
western equatorial Atlantic
Type level: Sample 926A-29-2, 141–143cm(13.429Ma), Zone NN5
Occurrence: Discoaster discissus ranges from mid
Zone NN5 (926A-30H-1, 79.5–81.5cm) to uppermost

233

Zone NN8 (Sample 926A-25H-5, 80–82cm) in the Leg
154 research, dated from 13.877Ma (error 0.008Ma) to
10.996Ma (error 0.012Ma). The HO of D. discissus has
been tied to the HO of D. deflandrei in only two GoM
wells; this stratigraphic horizon in upper Zone NN7 has
been dated at 11.575Ma in the Leg 154 research (Table 1).
Discoaster formosus Martini & Worsley, 1971
Pl. 7, figs 17–20
1971 Discoaster formosus Martini & Worsley, p. 1500,
pl. 2, figs. 1–8
Remarks: Martini & Worsley (1971) stated a size rangeof 15–19μm for the species; they described a prominent
star-shaped knob on one side, although this knob can besomewhat rounded. Discoaster formosus is distinguishedfrom other large mid-Miocene Discoaster species by its
pointed ray tips and prominent, high knob.
Occurrence: The HO of D. formosus has been calibrated to a local abundance cycle immediately below the
GoM stratigraphic horizon marked by the HO of theD. hexapleuros (knob), which is dated at 11.155Ma in the
Leg 154 research (Table 1). The actual HO of D. formosus in the Leg 154 research is in Sample 926A-25H-7,
10–12cm, dated at 11.212Ma (error 0.034Ma). The LOof D. formosus has been tied to the HRO of Cyclicargolithus bukryi in four GoM wells; this stratigraphic horizon in upper Zone NN5 has been dated at 13.706Ma in
the Leg 154 research (Boesiger et al., 2017; this volume).
The actual LO of D. formosus in the Leg 154 researchis in Sample 925B-34H-2, 90–91cm, dated at 13.756Ma(error 0.013Ma).
4.8 Cantinaster group
Genus Catinaster Martini & Bramlette, 1963
Six Catinaster taxa are included herein (Figure 7). Catinaster calyculus and C. coalitus were described from theupper Miocene of Trinidad by Martini & Bramlette (1963).
Peleo-Alampay et al., (1998) erected subspecies for boththese species based on the extension and orientation of distal central structures. Catinaster glenos and C. rotundus aredescribed from the same Trinidad collection (Bolli, 1957)
from which the genus Catinaster was erected over a half century ago. Catinaster rotundus, originally an Arco species, isessentially a round C. coalitus. Catinaster glenos is possibly
the ancestral species of this lineage (Figure 7). Peleo-Alampay
et al., (1998) indicated D. transitus was ancestral to Catinaster, whereas Self-Trail (2014) proposed D. virginianus as
the ancestral species. The morphology of C. glenos appears
transitional between D. virginianus and C. coalitus.
Catinaster glenos de Kaenel & Bergen, sp. nov.
Pl. 6, figs 11–16
2014 Catinaster virginianus Self-Trail (pro parte), p. 53,
pl. 2, figs. 2a–b; non pl. 1, figs. 1–12; pl. 2, figs. 1a–b
Derivation of name: From Greek glenos, meaning thing
to stare at, show wonder

234

Okada
Martini & Bukry(1971) (1980)

CN8b
NN10

Catinaster Group

CN8a

11.5

CN6

NN7 CN5b

Serr.

MIDDLE

11.63

NN6 CN5a10.85010.7329.760
HRO9.826

C. coal. coalitus

NN8

12.5

10.403

CN7a

11.0

12.0

CN7b

C. coal. coalitus (>10)

NN9

C. glenos sp. nov.

Tortonian

10.5

LATE

10.0

MIOCENE

9.5

inc10.403
LCO/LFO10.732

10.996

9.689

9.660

10.89310.963

9.781

9.689

LRO10.732

C. caly. rectus

9.0

C. caly. calyculus

8.5

Zone

C. rotundus
sp. nov.

Epoch/
Stage

C. coal. extensus

Age
(Ma)

de Kaenel et al.

10.732

11.531
Overlapping GoM/Leg 154 range
Extended GoM range?12.757

Figure 7: Range diagram of the genus Catinaster. Ranges and new ages for the NN (Martini, 1971) and CN (Okada & Bukry, 1980) zonations arederived from calibrations in ODP Leg 154 core samples as well as the Gulf of Mexico

Diagnosis: A basket-shaped Catinaster species having
thick distal ray bifurcations which touch or nearly touch.
Description: Small to medium-sized Catinaster species with a basket-like structure (seen in lateral view) andthick distal rays with broad bifurcations. The distal ray
bifurcations are thick and form obtuse angles. Their tips
are close to each other and may touch occasionally, but
do not fuse. In lateral view, the proximal periphery is notquite rounded.
Remarks: In lateral view, C. glenos has the typicalbasket-shaped structure of Catinaster but is also reminiscent of the proximal stem of many Discoaster species(Pl. 6, figs 15–16). Catinaster glenos is differentiated fromD. catinatus by having a very reduced proximal stem, butmore easily by having thick, bifurcate distal rays. Catinaster glenos is differentiated from C. coalitus by these thick,bifurcate distal ray elements. Catinaster coalitus has thin
distal ray elements with simple, pointed terminations.
Holotype dimension: 7.2#m
Holotype: Pl. 6, figs 13–14
Type locality: South Trinidad, Bolli (1957)
Type level: Sample Bo355, Globorotalia fohsi robusta
Zone, Cipero Formation, Zone NN7
Occurrence: Catinaster glenos was observed sporadically in samples from mid Zone NN6 (926A-27CC,

10–12cm) to lowermost Zone NN9 (Sample 926A-25H-4,
56–58cm) in the Leg 154 research, dated from 12.757Ma(error 0.033Ma) to 10.850Ma (error 0.017Ma). The HO
of C. glenos has been tied to the HO of Discoaster hexapleuros (knob) in three deepwater GoM wells; this stratigraphic horizon in upper Zone NN8 has been dated at
11.155Ma (Table 1).
Catinaster coalitus coalitus Martini & Bramlette,
1963
Pl. 6, figs 17–21
1963 Catinaster coalitus Martini & Bramlette, p. 851,
pl. 103, figs. 7–9
Remarks: Catinaster coalitus extensus is differentiatedfrom C. coalitus coalitus by having rays which extend
outside the central area periphery. Catinaster glenos has
thick, bifurcate rays. Catinaster coalitus is distinguishedfrom C. rotundus by its hexagonal peripheral outline.
Occurrence: The LO of the species C. coalitus marks
the base of Zone NN8 of Martini (1971) and Zone CN6 of
Okada & Bukry (1980). This event was difficult to placein the Leg 154 research because specimens are almost
always oriented in lateral view, indicating that specimens
are taller in the lower part of the stratigraphic range ofCatinaster. The LO was dated at 11.531Ma in the Leg 154

…Discoaster and Catinaster taxonomy and stratigraphy…

research (Table 1), comparable to its position in deep-water GoM wells. The HO of C. coalitus is a GoM marker,
but this stratigraphic horizon has been equilibrated to the
HRO of C. coalitus in the Leg 154 research and dated at
9.826Ma (Table 1). The underlying GoM stratigraphic
horizon is marked by the HO of large C. coalitus (>10#m)and the first downhole increase in C. coalitus. These two
events are dated at 10.403Ma, equilibrating the first downhole increase observed in GoM wells to the HCO in the
Leg 154 research (Table 1). The LO of large C. coalitus
corresponds to the LCO of the species in the Leg 154
research, in which these two events are dated at 10.732Ma(Table 1). The LCO of C. coalitus has been applied indeep-water GoM wells (Table 1), whereas the LO of large
C. coalitus is not yet established in the GoM.
Catinaster rotundus de Kaenel & Bergen, sp. nov.
Pl. 6, figs 22–24
Derivation of name: From Latin rotundus, meaning circularDiagnosis: A small to medium-sized Catinaster species. In plan view, the species has a circular peripheral
outline and six straight rays that extend from the center
to the rim.
Remarks: Catinaster coalitus coalitus has a hexagonal periphery, whereas Discoaster catinatus has a serrate
periphery. Catinaster rotundus has been referred to as“C. coalitus (round)” in the BP/Arco GoM lexicon.
Holotype dimension: 6.7#m
Holotype: Pl. 6, fig. 22
Type locality: South Trinidad, Bolli (1957)
Type level: Sample KR23422; Globorotalia menardi
Zone, Lengua Formation, Zone NN9
Occurrence: The HO of C. rotundus has been
observed immediately below the HO of large D. hamatus(>15#m) in two deep-water GoM wells; this stratigraphic
horizon in upper Zone NN9 is dated at 9.618Ma in the Leg
154 research (Browning et al., 2017; this volume). Catinaster rotundus was observed very sporadically in samples from lower Zone NN9 (926A-25H-4, 107–109cm) to
upper Zone NN9 (Sample 926A-24H-1, 75–77cm) in the
Leg 154 research, dated from 10.893Ma (error 0.027Ma)
to 9.689Ma (error 0.010Ma).
Catinaster coalitus Martini & Bramlette, 1963
extensus Peleo-Alampay et al., 1998
Pl. 6, figs 25–26
1998 Catinaster coalitus extensus Peleo-Alampay, Bukry,
Liu & Young, p. 83, pl. 1, figs. 8–9; pl. 2, figs. 19–20;
pl. 3, figs. 1–6
Remarks: Catinaster coalitus extensus is differentiatedfrom C. coalitus coalitus by having rays which extend
outside the periphery.
Occurrence: In Leg 154, C. coalitus extensus ranges
from Sample 926A-25H-5, 80–82cm (10.996Ma; error
0.006Ma) to Sample 926A-24H-2, 139–141cm (9.781Ma;
error 0.021Ma). The HO was observed between the HO

235

of the new species Discoaster caulifloris (Browning
et al., this volume) and the HO of large Discoaster hamatus(>15μm) in three deep-water GoM wells; these two successive Discoaster marker events were dated at 9.542Ma
and 9.618Ma in the Leg 154 research (Browning et al.,2017; this volume).
Catinaster calyculus Martini & Bramlette, 1963
rectus Peleo-Alampay et al., 1998
Pl. 6, figs 27–28
1963 Catinaster calyculus Martini & Bramlette (proparte), p. 850, pl. 103, figs. 2–3; non pl. 103, figs. 1, 4–6
1998 Catinaster calyculus rectus Peleo-Alampay, Bukry,
Liu & Young, p. 84, pl. 1, figs. 10–15; pl. 3, figs. 7–11
Remarks: Catinaster calyculus rectus has straight rays,
whereas the rays of C. calyculus calyculus are curved.
Catinaster coalitus extensus also has straight rays which
extend outside the central periphery but bisect the hexagonal sides of that periphery.
Occurrence: Catinaster calyculus was not differentiated into subspecies in GoM wells. In Leg 154, it ranges
from Sample 926A-25H-3, 67–69cm (10.732Ma; error
0.020Ma) to Sample 926A-24H-1, 75–77cm (9.689Ma;
error 0.010Ma).
Catinaster calyculus calyculus Martini & Bramlette,
1963
Pl. 6, figs 29–30
1963 Catinaster calyculus Martini & Bramlette (proparte), p. 850, pl. 103, figs. 1, 4–6; non pl. 103, figs. 2–3
Remarks: Catinaster calyculus calyculus has long, curved
rays that extend from the corners of the hexagonal basket.
Occurrence: In the Leg 154 research, C. calyculus
calyculus ranges from Sample 926A-25H-5, 44–46cm(10.963Ma; error 0.021Ma) to Sample 926A-24H-1,
10–12cm (9.660Ma; error 0.030Ma). The LRO of C. calyculus calyculus was dated at 10.732Ma (Sample 926A25H-3, 67–69cm; error 0.020Ma) in the Leg 154 research.
The HO of the species was observed between the HO of
D. caulifloris (9.542Ma) and the HO of large D. hamatus(9.618Ma) within lower NN10 (Browning et al., 2017;
this volume) in four deep-water GoM wells.
5. Depository
The slides and samples are stored in the micropaleontological collections of the Natural History Museum inBasel (NMB) in Switzerland. Also curated at the NMB are
the samples of the foraminifera collections of H.M. Bolli(1957), which have been used to describe several of the
new species herein. Type material from DSDP and ODP
cores are also stored at the Bremen repository (Germany)and the College Station repository (USA).
Acknowledgements
We are grateful to BP GoM Exploration for their supportand encouragement in the publication of this research as

236

de Kaenel et al.

well as Graham Vinson, Liz Jolley, and John Farrelly. We
are appreciative of the BP GoM teams in Exploration and
Production. These groups were fundamental in integration
and application of these biostratigraphic events for subsurface description. The authors would like to also thank BP
for its financial support of the ODP Leg 154 sampling andresearch as well those involved in the acquisition, preparation, and analyses of materials involved in this study.
We’re also grateful to the Integrated Ocean Drilling Program for the use of ODP Leg 154 materials. Of course,
we’d like to thank the authors’ families for their patienceand support as these five papers were concurrently written and reviewed. We would like to thank Walter Hale atthe IODP Bremen Core Repository (BCR) for the help insampling the Leg 154 cores. We also thank Diane and Linede Kaenel for helping to process the ODP samples. Many
thanks to Richard Howe and Richard Denne for reviewing
this paper.
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Plate 1
NN5

2!m

1

925D-35-1,75-77

Discoaster druggii (<10)

NN52925C-35-3,120-122

Discoaster druggii (<10)

6926B-40-4,140-142

925C-35-3,120-122

7926B-40-4,140-142

NP26

4

NN3

8

926B-50-5,140-142

Discoaster druggii (<10)

926B-39-5,35-37

NN2

5

NN2

9

926B-40-4,140-142

Bo267

Discoaster druggii (10<15)
NN2

10

Bo267

Discoaster druggii (10<15) Discoaster druggii (10<15) Discoaster druggii (10<15) Discoaster druggii (10<15)
NN3

11

3

Discoaster druggii (<10)

NN2

NN2

Discoaster shumnykii

NN5

D. druggii
bUD@a

12

926B-38-6,
135-137

NN2

NN2926B-40-4, 140-142

NN3Discoaster shumnykii
NN2

17
NN2

13
Discoaster druggii bUD@a

926B-40-4,
140-142

14
D. druggii bUD@a
NN2

15

Discoaster druggii bUD@a

926B-40-4,140-142

926B-39-1,5-6

NN2

16

Discoaster druggii bUD@a

Bo267

18

Discoaster druggii bUD@a

Bo267

…Discoaster and Catinaster taxonomy and stratigraphy…

239

Plate 22!m1

D. kugleri

NN7926A-26-2,
141.5-143.5

NN72

D. kugleri

NN76

D. kugleri

926A-26-2,
141.5-143.5

7

NN7

HOLOTYPE

11

Bo355

12

NN7

GoM

17

HOLOTYPE

NN7

HOLOTYPE

21

Bo355

22

D. cuspidatus

NN7

26

D. cuspidatus

Bo355

D. kugleri

8

D. kugleri
NN7

HOLOTYPE

926A-26-3,
107-109

4

D. kugleri

926A-26-2,
141.5-143.5

18

9

NN7

D. cuspidatus

926A-26-2,
141.5-143.5

D. cuspidatus

926A-26-3,
107-109

10

NN7

15

NN7

19

NN7

20
NN7

24

NN7

25

29

D. cuspidatus

926A-26-3,
107-109

D. cuspidatus (knob)
NN7

NN7

28

926A26-3,107-109

D. hexapleuros (knob)

NN7

23

Bo355

NN7

NN7

14

Bo355

5

D. kugleri (transitional D. cuspidatus)

NN7

D. hexapleuros

NN7

NN7

NN7

13

NN7

27

926A-26-2,
141.5-143.5

NN7

NN7

NN7

16

D. hexapleuros

3

NN7

HOLOTYPE

D. hexapleuros

926A-26-2,
141.5-143.5

NN7

926A-26-3,
107-109NN730

D. cuspidatus

GoM

240

de Kaenel et al.

Plate 32!mNN3

HOLOTYPE

NN2 HOLOTYPE

2

Bo267

D. shumnykii

1925A-15-4, 60-62

6

926C-7H-6, 114- 116

926A-26-2,141.5-143.5

D. obtusus

HOLOTYPE

NN2

HOLOTYPE

11

Bo267

12

Bo267

NN3

8

D. calculosus

926B-38-1,70-72

9D. leroyi

13926B-44-2,115-117

D. nephados
NN2

12.80!m
Bo267

17
D. salomonii

18.05!m
Bo267

NN3

925A-15-4,110-111

NN2

5

14

D. deflandrei

926B-37-3,15-17

13.40!m
926B-38-6,40-41

1818.50!m
926B-38-6,40-41

NN5

926A-29-5,80-82

NP25

15

D. deflandrei

926B-53-6,90-91

NN2

19

15.50!m
Bo267

D. calculosus

NN3

D. calculosus

10

D. leroyi

NN3

D. calculosus (<15)

21

HOLOTYPE

NN3

NN2

NN2

20

Bo267

D. shumnykii

NN2

NN2

D. deflandrei

4

D. obtusus

D. salomonii

16

3

NN7

7

NN2

D. shumnykii

NN18

D. obtusus

NN2

NN3

22

…Discoaster and Catinaster taxonomy and stratigraphy…

241

Plate 4
2!m

NN2

1

Bo267

D. saundersii
HOLOTYPE

62

D. saundersii

NN6926A-27-1,131-133

D. emblematicus

11

GoM

NN7

16

GoM

D. ulnatus

7

NN6

HOLOTYPE

NN6

HOLOTYPE
HOLOTYPE

17

JS32

18

13

D. patulus

NN4-NN522

HOLOTYPE

NN5

HOLOTYPE

926A-29-4,19-21

8

27

GoM

D. emblematicus

HOLOTYPE

D. ulnatus

Bo267

HOLOTYPE

NN2

4

Bo267

D. durioi

NN7

GoM

GoM

26

3

D. saundersii

12

D. patulus

21

D. carneyi

926A-26-3,107-109

D. emblematicus

NN4-NN5

D. musicus

Bo267

NN7

NN6

D. patulus

NN2

NN2

23

NN5

9

28

Bo267

NN7

10

D. emblematicus
NN6926A-27-4,13.5-15.5

NN6

HOLOTYPE

HOLOTYPE

19

D. ulnatus

GoM

GoM

NN6

14

24

29
D. carneyi

GoM

NN6

15

D. sanmiguelensis
NN6

NN5

926A-29-3,52.5-54.5

20

926A-27-1,131-133

D. sanmiguelensis

NN5

NN4-NN5

NN6

D. carneyi

5

D. durioi

NN7

NN4-NN5

D. musicus

NN2

25

GoM

30

926A-29-4,19-21

D. musicus (transitional)
NN6
NN5

GoM

D. carneyi

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de Kaenel et al.

Plate 5
Self-Trail (2014)2

1

D. virginianus

NN5

2!m

926A-29-2,141-143

926A-29-5,80-82

D. gamberi

NN57926A-29-5,80-82

926A-29-5,80-82

NN5

HOLOTYPE

16

4

926A-29-5,80-82

NN58

926A-29-5,80-82

D. gamberi

NN5

11

NN5

12
NN5

17

9

NN5

13

HOLOTYPE

HOLOTYPE

HOLOTYPE

NN5

NN5926A-29-2,141-143

925C-35-3,120-122

D. premicros
NN6

D. stellimicros

GoM

NN5

22

14

NN5

NN6

27

926A-27-7, 11.5-13.5

D. stellimicros

NN4-NN523

GoM

HOLOTYPE

NN628

926A-29-4,19-21

NN5

10

926A-29-5,80-82

NN5

15

NN5

19

D. premicros

HOLOTYPE

HOLOTYPE

NN5

D. catinatus

18

HOLOTYPE

5
D. gamberi

926A-29-5,80-82

D. catinatus

HOLOTYPE

26

GoM

NN5

D. gamberi

D. catinatus

21

NN6

D. virginianus

D. gamberi

D. catinatus

3

D. virginianus
NN5

6

NN5

20

NN5

24

GoM

NN4

25

D. arneyi

29926A-25-5,80-82

PJ260

NN9

NN8

D. transitus

926A-29-5,80-82

D. catinatus

HOLOTYPE

D. arneyi

NN530

D. transitus

KR23422

…Discoaster and Catinaster taxonomy and stratigraphy…

243

Plate 6
2!m

NN7

1

NN7

3
NN7

2

Bo355

D. micros

11

HOLOTYPE

Bo355

C. glenos

HOLOTYPE

14

21

GoM

C. coalitus coalitus
HOLOTYPE
NN922
C. rotundus

KR23422

6

8

Bo355

16

GoM

18

926A-25-5,80-82

26

GoM

28

20

KR23422

NN9

NN9

NN9

29calyculus926A-24-3,20.5-22.5
C.
calyculus
NN9926A-25-1,35-37

C. calyculus rectus

NN9

C. coalitus coalitus

27
NN10

C. coalitus extensus

NN9

19

C. coalitus coalitus

25

GoM

NN8

NN10

NN9

10
D. catillomicros

17

sample number
GoM

NN7

NN8

NN7

C. glenos

NN7

9

NN7

15

23

24

NN7

D. catillomicros

NN9

C. rotundus

HOLOTYPE

Bo355

NN7

Bo355

NN7

7

NN7

C. glenos
NN9

NN7

D. micros

13
NN7

12

Bo355

D. micros
NN7

HOLOTYPE

5
NN7

4

NN7

30

926A-24-3,20.5-22.5

C. calyculus calyculus

244

de Kaenel et al.

Plate 7
NN5

2!m

1

925C-34-4, 30-32

D. petaliformis

NN5

2

NN4

3

NN4

4

925C-37-1, 140-141

D. petaliformis

NN5

NN5

NN5

NN4

8

5

925C-34-4, 30-32

HOLOTYPE

NN5

D. petaliformis

9

D. apetalus

926A-29-4,
116-118

6

HOLOTYPE

10

7

GoM

D. petaliformis
HOLOTYPE

925C-34-4, 30-32

NN5D. petaliformis
NN5

NN5

11

900A-20R-2, 89-90

D. apetalus

NN5
NN5 NN6

12 D. discissus

926A-29-2,141-143

NN6

13 D. signus

14925B-34-3, 11-12

D. signus

NN5925B-34-3, 11-12

15

926A-28-1,86-88

D. signus
NN5926A-28-1,86-88

NN5

16

926A-27-1,131-133

D. discissus
NN517

D. formosus

926A-29-2,141-143

18

19

D. formosus

926A-29-2,141-143

20

D. formosus

900A-20R-2, 91-92